A few things to consider:
1) Have you taken the MCAT? Make sure to give yourself enough time to study! I would recommend that you study during a summer while you're not enrolled in school full-time so that you have more time and fewer responsibilities, which ideally will allow you to perform much better on the test. However, you also want to apply as early as possible in the cycle (i.e. early June
of whichever year you're planning to apply during), so studying from May-August of your application year, taking the MCAT in August or September, and then applying for that cycle in the fall is not a good idea.
I personally studied for the entirety of the summer after my sophomore year (while working as a scribe for ~30 hours a week) and took it that August so that I could apply early June after my junior year. I am mostly happy with this decision, as it gave me lots of time while still allowing me to apply on the first day AMCAS opened (which is crucial so that you are verified faster and then reviewed by schools sooner). However, I took the MCAT without having taken half the pre-reqs, and that was definitely a poor decision on my part. So, I guess the moral of the story is: if you are done with the pre-reqs after your sophomore year and have a fairly uninterrupted summer, study and take the MCAT then so that you have the option of applying after junior year! But I would recommend against applying the same cycle that you take the test (e.g. taking the MCAT in the summer after junior year and then applying that fall), because it'll cause you to be complete quite late at the schools you apply to. Besides, if you aren't happy with your score, you're unable to retake and still apply that cycle because there won't be any more tests offered after you get your score back and you will have theoretically already submitted your applications by that point anyway.
2) Interviews are very time consuming. I was expecting to get 0-5 interview invites and instead I got 16 invites (attended 14 interviews), and was therefore gone for a LOT of my fall semester senior year. I literally missed between 1/3 and 1/2 of my classes. It was expensive, time-consuming, and stressful. An amazing experience, for sure, but it created a lot of strain on my schedule and my grades suffered as a result. Like I said, I honestly was not at all anticipating such an intense travel schedule, so I want you to keep that in mind as a possibility when thinking about applying during your senior year and how you might be able to balance interviews with your classes and extracurriculars.
3) It seems like nowadays, most people take a gap year or two (or more!), so they have a few more years of experience to put on their applications. It's difficult for someone with only three years of activities to compete with that. Someone who has since graduated may have had the opportunity to put extensive time and effort into something impressive or that they are passionate about, whereas you haven't had that option since you've been busy with school for the entire time leading up to your application. It's certainly possible to get in straight from undergrad, but I do believe that it's harder to stand out because it's likely that you won't have had as much experience.
4) Make sure you're not going to burn out. Unless you took time off between undergrad and college, you've been in school non-stop since age 3 or 4. Most people I've talked to have said that a break has been really refreshing and allowed them a bit more time to relax and catch their breath before heading into the intense pressure-cooker that is medical school. However, others said that it was hard to integrate back into the classroom after stepping away from that setting for a long period of time, so I guess there are two sides to that story. I personally decided to go straight through to med school, and while I'm happy with that decision overall, some part of me does wonder if I would have benefited from a year off. I didn't really ever even consider the possibility of a gap year, and I guess I wish it's something I had seriously considered.
5) You said "top medical schools". It's totally fine to aim high, as long as you realise that all medical schools are good. I don't know you or your motivations, so I'm not saying you necessarily fall into this category, but I see a lot of people posting on SDN that have all of their hopes and dreams pinned on going to a top 20 or top 10 or top 5 medical school. You can't make all of your decisions or determine your self worth based upon the whims of any particular institution or even a certain tier of institutions. Going into an app cycle with the mindset that you will be unhappy unless you matriculate at an uber prestigious, highly ranked medical school is pretty unhealthy. Again, this isn't meant to be offensive, nor am I saying that you aren't "top school" caliber. Just speaking from personal experience, it's all too easy to get caught up in rankings and lose sight of what really matters, which is not prestige but instead fit and opportunities. It's something to keep in mind, that's all.
I hope some of this helped! Best of luck to you in your decision
Feel free to let me know if you have any other questions, as I can provide more perspective on my process as a traditional applicant!