I had the same symptoms during my 2wws that were BFN and my 2ww that was BFP (slightly sore boobs and crampy - no implantation spotting). They were IVF cycles and I was taking progesterone so after the first BFN I attributed the sore boobs and crampiness to that. The third IVF, I was so convinced I wasn't pregnant I made a consult with another RE. I decided to take a HPT 5 days before my beta... I was having cramps just like my period was coming that morning so was sure it was going to be a BFN, but I couldn't take the wait anymore. Was totally shocked at the BFP. My nurse had me come in the next day and my beta was about 600. 8w4d and counting the hours until my next ultrasound. The wait to make sure there is still a heartbeat and a growing baby is almost as bad as the 2ww. Good luck, ladies!