So for the past week I have had cramps/pressure in my lower stomach. I've been drinking tons of water so I don't think its a bladder infection. The cramps come and go. I'm not ovulating. I just got done with that. Also another weird thing was 5 days after the last day of my period I had major mood swings for about two weeks now. I'd like to note that I have been very sexually active and I am not on birth control and also we never use a condom. What could this be?