Well i dont really know much about this type of pill, but I went to the docs about my abnormal periods too, and found out I had polycystic ovaries, and they supplied me with a contraceptive pill to regulate my period.
It worked, and me and my boyfriend have sex without condoms and we have been fine. I think most pills are 99% are'nt they? Oh well, i dont think they would have called it a contraceptive pill if it didnt do its job right.
Maybe if you do find problems, you should go back and see the gyno, without your mum maybe? He may have asked you if you have had sex before for a reason, I remember the doctor asking me, but I hadnt at that time so she didnt explain why she asked either.
Hope you get your queries sorted.