Weird bleeding???

This may be long, just got off BC late November, first cycle was 40 days, second cycle I had peak OPK on day 20... cycle day 28 I had pin size spot of old blood and pink blood, day 29 & 30 more old blood wore one panty liner all day spot size of half dollar, today cycle day 31... brown spotting with some light pink, put a tampon in thought start of AF, 5 hours later nothing. What is going on?