My birth control Nexplanon expired February 12th 2016.. I have not gotten it taken out yet. I was supposed to have a period the third week of February and i have not started yet. But i have been spotting for a little over a week. After i use the bathroom I wipe and sometimes I will have pink on my toilet paper but sometimes I will not have anything.. should I be concerned that I could be pregnant or is that just the birth control messing up on my cycle??