Question

Hi, I've been trying for two years to get pregnant with the use of sperm donors (both frozen and fresh) my menstrual cycle lasts 28 days and I don't usually get cramps. This cycle, I my period was due on Oct. 26th, but it started three days early on Oct. 24th and two days prior to that, I had slight brown spotting after using toilet paper. On the day I started my period early, I of course didn't expect it and I started having this burning feeling in my abdomen (from the area where my uterus would be, all the way up in my abdomen area) and the next day, I was in severe pain for quite a while. A week before my period started I had indigestion, burping (never happens to me), tender breasts, lower back pain. I've taken two pregnancy tests...one a day before my period was due and one the day my period was to happen originally and they have been negative. My period hasn't been as heavy this time around, but I have had small clots. Seems like I was pregnant - could I still be? Advice?