Please shed some light on this!!?

I am approx 10dpo... my period was 18th Jan and i was due to ovulate on the 30th- 3th Feb... FH and I did the BD for 3 of these days. However, on the 30th and 31st I was bleeding. (sorry TMI) I was really confused and emotional as I wasnt sure if it was a period again and would make me have to wait another 3 weeks to ovulate again etc etc. Now my fiance is away for work for 2 months... I am experiencing white lotion like CM.. and have very heavy . Cramping in lower back and right and left sides. Not all the time but really bad today. Could be AF but not due for another 5 days. (going by my normal cycle) Had light pink spotting mixed with CM last night and almost yellowish. Did a test and came out very very faint BFP. HOWEVER, I was not sure about the test as i did it in the evening. So I did 2 more with FMU... and both negative. So I am confused. Feeling a little sick but could be the cramping.. I hate the TWW!! Why did I bleed at ovulation?? And why did I test faint BFP to then test BFN??