Cramps, Nausea, Pelvic Bone Harder. Pregnancy Test Negative. What Is The Reason For Symptoms?

hi, i had a period that started on about june 29th, around july 15th i started cramping a little and spotting off and on for about a week and a half -two weeks, it stopped for a few days and then i had a slighty shorter period on July 27th. The cramps have been random but continues sense it started back in july and some can be quite sharp at times. I am exhausted pretty much all the time, i get nasuas almost every night and as of yesterday right above my pelvic bone is alot harder then normal. I took a pregnancy test 2 days ago and it was neg. I have a 4 yr old daughter, and she was a negative too :P, but i had no other symptoms with her either. I am curious for a professional opinion of what might be going on with me. I have a Dr. apt in 4 days but I would like to know what to expect going in there and possibly what to ask for if/when another test comes up neg.