Pain after masturbation..

OK, so I have never had this problem before it started probably 3 to 4 weeks ago. I was masturbating only external nothing internal whatsoever. Well everything felt normal. Everything was great and then, as soon as I started to orgasm, there was discomfort and almost like a pain I can’t explain it was just like almost like a period cramp like a bad period cramp pain afterwards well that is happened every time sense what is going on? Has this happen to anybody else? I don’t know what’s going on and not related to masturbating I will be totally fine and then I will get a sharp pain below my belly button, but above my pubic bone randomly and then it’ll go away anybody have any clue what’s going on or what I should do..?