I will graduate in May with a BS in biology/chemistry but while a degree probably helps i dont think it is necessary to be competitive (i tried to find stats on this but was unsuccessful). if you are well-rounded and have a good application (not just good gpa/pcat, but pharmacy experience in different areas, volunteer/extra curricular activities, leadership positions, and great LORs etc) than you should be competitive whether you have a degree or not. Because I can tell you it wasnt my gpa and pcat that got me in lol, oh and an awesome personal statement couldnt hurt 🙂.
So dont worry about applying as a junior, if you are well-rounded you should be fine and it is worth a shot, if you get in, Great! if not it will be good experience for applying the next time and you will know how you can improve by either working towards your degree or gaining more experience. Just keep working towards your goals! Good luck!