I have problems,I got my period when I'm 12,then now I'm 23 when it stop when I get 16,then it became irregular until no. like 6 months I don't get it.. and worst a year.. is it possible for me to get pregnant.I had a husband.and wer trying to conceive.I had my period oct. 20 and we do it on nov. 8 and he did it inside me 3 times.then I felt this pain in my lower back and some in my pelvic area.I test 4 weeks after we did it.but it came negative.but still the pain came.. no more any symptoms.is it my mind only?

You need to discuss this with your OB/Gyn. Only thorough testing to determine why your periods are irregular and, possibly, a regimen to try and get them more regular, can help you get pregnant.