period question

I had my mirena iud removed June 2... my first period lasted 3 days..second month started same day so I guess you can say they're regular.. but this time my first day I spotted all day long. didn't start bleeding till next day. bled for two days. then spotting half the next day and bled the rest and the last day I just spotted..what could this mean? my fertile window started is today and we've had sex the past 4 nights..my ovulation day ain't til the 20th..I don't get what's going on.. were ttc for baby #2..