On Junel Fe Missed A Few Doses, 3 Days Late

On Junel Fe missed a few doses, 3 days late on period and no normal pms symptoms I was just tired, emotional and got a cold. I got a Faint positive line three days ago (Friday) on a pregnancy test. Next day, slight cramps, spotting and some white clots!. Then spotting for 2 days, not like my usual period. Took a pregnancy test yesterday and it was negative. What are the white clots and what is going on? This isn't a normal period and I'm apparently not pregnant.