Welcome chatterbox! (My Italian grandmother used to call me that too, only it was in Italian.)
Yes, see a doctor. From a purely medical standpoint you should see one for the reasons noted by the previous poster.
Please also pick up a copy of the book, Fertility, Cycles, and Nutrition, by Marilyn Shannon. She has some wonderful ideas for treating PMS. She gives her views as a nutritionist and a Catholic. Your doctor might not have good information for treating PMS. The “standard treatment” is usually hormonal changes from birth control pills. This doesn’t fix PMS it only masks it.
So as to your other concerns. Before I say anything, I want to say how absolutely impressed I am that you are living a good chaste life. I wish many times that I had better understood the Truth that the Church had for me to learn, before I went out and made such horrible decisions. We are the same generation and yet you made the right decisions.
Now with that said, you are suffering from some secular untruths just like I was. You just made better decisions with your information than I did. Society has taught that losing one’s virginity is defined by breaking one’s hymen or other such things. It is so sad that untruth is out there. The truth is that the hymen is an elastic membrane. It is meant to be stretched, not broken or torn. A torn hymen means something went a little wrong or a lot wrong. Even childbirth can be done without a torn, or cut hymen. The cervix, which is barely even opened by the speculum (spelling is wrong there) stays the same until you have a baby even in the sexually active. (Before learning NFP, I didn’t even know where my cervix was or what it did.) And believe me, most of the secular world who think they know so much about sex do not know either!
We as Catholics know that secular “sex ed” is one big joke. It teaches nothing that is Truth. It makes people afraid to ask the real questions. The world of sexual repression does the same thing. I would suggest a deep study of “Theology of the Body” by our late Holy Father, Pope John Paul the Great for a deep understanding. The book, Theology of the Body for Beginners, by Christopher West is a good starting point. It is pointed out in TOB that the world of sexual indulgence and the world of sexual repression are just two sides of the same coin and neither one is even close to Church teaching. Once I learned this theology it made me want to go out and learn the real Truth of the human body and soul.
“Virgin” means untouched. What a doctor does in a routine exam does nothing to violate that. Please remember that the most important sexual organ is the brain. A doctor is not approaching you in a sexual manner. He or she is approaching you in a purely medical way. If you would like to discuss and understand more please feel free to PM me if you are not comfortable in this public environment. Don’t be embarrassed for being naive. At least you are naive and NOT acting on it. I was naive and stupid! God has given me the graces to overcome my terrible past and use it to spread the Truth found in His holy, Catholic Church.
God bless you.