What could be causing bothersome uterus pain?

Hello, need a bit of help. I m 27 and feel my uterus is bothering me. I m not sexually active(still a virgin) and have irregular periods. I went to my Gyneogologist Doctor and told him that I was feeling odd cramps but wasn t on my period. I was a month late due to irregular periods. So he did a urine sample and he said everything looked fine but wanted an ultrasound. He gave me pills to take care of something called vaginitis those pills worked. But I did the ultrasound part one was normal but the next part the lady needed to stick a probe inside. It was very painful they had to stop. A few hours I went walking and I over did my excerise. But now I was trying to sleep but it is bothering me. I keep getting up to pee every 4 mins and it s just little drops I have no pain when I pee it just bothers me. I have the feeling like I need to go. But the pain is not extreme or that minor it just bothers me I can feel a slight bothersome pain like I need to go but nothing is there. I do have IBS. However I ve always been healthy in that area now suddenly this what can it be?