Spotting After Intercourse

Today I am 7wks 1 day by Glo's calculations. Last week, after I/C, I spotted light pink, with a bit of brown the next day. Since then I had a 6week interutero ultrasound, and everything was "normal". My husband and I held off of any activity again until yesterday afternoon, and although I didnt notice any of pinkish spotting this time, there were small spats of the brown spotting again. This is all pretty nerve wrecking. I will ask my Dr. about this tomorrow, but wanted to know what others experiences were with this scenario? I do have PCOS, and am taking low dose of metformin as precaution. Thanks for any input.