Yesterday early morning woke up in a sweat from sharp pain in the center of my uterus. Usually when I've had cramps I only get them on one side. Tested and bfn. Today I have lots of cm and when I put my finger up there, it seemed like a little bit of pink. Tested again bfn. Today is 15 dpo and have had tender and swollen breasts all this tww. I'm very irregular so not sure when af is due but I've never had swollen breasts this long. Could I have experienced implantation yesterday morning and seen  implantation bleeding today? I'm driving myself nuts! I guess I could have O'd later... didn't temp just used digital OPK and got blinking smiley on Jan 18th.