Okay you are conflating "feminine" with "beta."
Yes - most PEOPLE in medical school are pretty damn alpha, regardless of gender. I can imagine that there are male medical students (such as yourself) who may find this to be an intimidating/unattractive quality in your female classmates, especially since your frail ego seems to require women to play a subservient role to you in order to be "feminine" or "attractive." But I assure you that there are plenty of dudes in medical school who do not think this way/have these insecurities.
Personally, the type A personalities of most medical students and law students make them too difficult for me to date but it isn't because they aren't "feminine." It's because I have a go-with-the-flow mentality that doesn't mesh well with most professional students - they stress me out. That doesn't mean that they aren't great catches - in fact, I have helped play matchmaker with a handful of professional students and it seems to work out relatively well.
If what you're looking for is a stereotypical feminine role, I suggest you either get a time machine back to the 1950s, look into a mail-order-bride from Eastern Europe, or find yourself a gold digger and be prepared to lose half of your money in 25 years. Otherwise, put on your big boy pants and realize that women are your equivalent and they don't need to be docile in order to be attractive.