I think that even if your boyfriend only put it inside you for less than two inches, you are not a virgin, technically. I don't think a gynecologist would be looking to see if you are a virgin or not. The amount of bleeding does not make you a virgin or not. It is somewhat normal to sometimes skip a month of your period.
Why are you worried whether or not they can tell? If you are worried about someone finding out...don't! They are not allowed to tell...ANYONE. Parents, boyfriend, doesn't matter. It's called doctor-patiend confidentiallity. You should ALWAYS be honest withyour doctor...they aren't going to judge you and they wont talk about you and they wont tell anyone...but they can't help you any if you lie.
(p.s. if you have a gyn that make you feel like he/she is judging you then you need to find a diff gyn!)
oh...and no you are not a virgin. But don't worry too much...it happened...and you can't go back and change it, so dwelling on it does you no good...you need to start walking foreward instead of looking back!!! If it is something you regret then at least you know it's something you want to wait a little longer to do but it's not like it makes you a bad person...look at this as a learning experience!
best of luck.
...and we can't answer whether it is normal to miss a month on your period because we don't know your cycle. Do you normally have a reg. cycle? Do you keep track of your cycle. If so, are you ever off? Are you on the pill and if not, and you have irregular cycles you should consider it to make them regular.
hope this helps