Stabbing pain when AF is due

Emily

Ok... I have a normal 5 day cycle. I was expecting AF on Tuesday she arrived on Sunday(2 days early) with no signs I was about to start it was watery and it was light maybe 4 tampons(3reg and 1 lite) for 2 days then nothing. I had a sharp painful cramp on Tuesday when I was supposed to have AF I mean it radiated to my back and a dull pain after for only about 5min after the sharp pain. We have been TTC for over a year. My nipples are now itchy and dry and flaking. Anyone have this happen and get a BFP? I took a PT today and negative. I am so confused.