From like day 3-7 past my positive opk I had cramping and mildly tender breasts but then it all stopped. Today I'm 10dpo and I've got this really light bleeding (dusty rose) but no cramps what so ever (which isn't like me) and a clot maybe the size of a pinhead. This is my first month on Metformin and 14th month ttc so I've tried Soooo hard to keep my hopes down and chalk everything up to Metformin side effects. Could this really be happening? If it is implantation, how long should I expect it to last?