Stomach pains, but no hymen?????

Well, considering that it was her first sex, her abdominal pain could be associated to the fear and could be mental.
Another problem could arise from the fact that your penis may be too big for her insides or that you were a bit harsh, or that you didn’t choose proper positions, etc

Sometimes, when my boyfriend hits the uterus I get pain in the ovaries but it goes away soon after. How long did she experience the pain? Did it hurt after intercourse as well?

Try taking it slow next time, make sure her vagina is wet or lubricated, so that things could go smoothly, ask her if she has any fears (of getting pregnant, hurt, etc) and use condom to make her feel safe.

Be gentle and see if the problem persists. Remember what kind of pain it is, where exactly it is, how long it lasts, etc

If the problems continues, she may need to see a doc and have a pelvic examination to see if everything was in order or of the pain is just psychological.

my gf is having same prob
nd same happend to my ex nd she was a week lat eon her period but would it be stress related pains ?
like she started pains day after we had sex for the first time