Possible desidual bleeding?

I've been on ortho-cyclen (28 day cycles) for few years to lighten my periods and birth control. I missed a few random pills in Oct. but had a normal period Oct. 22-25.. two weeks before my next period was due my breasts began to ache throughout the day and became really sensitive to touch. I have a good supportive bra so I know that's not the reason. Over the next couple weeks before menses due my breasts felt heavier and swollen, bra felt tighter, nipples always erect, areolas darkened, sensitive to smells, I began to use the restroom more often to the point of every 2-3 hrs, I lost appetite for food because I became very nauseated, almost to vomiting, especially in the evenings. I also had dizziness, odd taste in my mouth, mood swings, clear mucus like discharge. My periods usually start tues-wed, but I only started spotting Thursday evening and stopped early Saturday morning on 11/24. I had sex that night w my hubby, 2-3 am, and took an hpt w fmu @ 7am, came out negative. Used the restroom half hour later and was dark red blood and single clot, stopped after few minutes, no cramping. I still see a little pink when I wipe, but liners stay clean. I've never had a period like this, nor have I had so many saying possible pregnancy. I did miss a couple pills in a row around the time I should have ovulated, still having preggo like symptoms. Could this be a strange period or desidual bleeding?