Could Delayed Periods Be Due To Pregnancy In Women Having PCOs?

Hello I recently had baby #2 in jan of 2014 6 weeks later i had the merian put in well this past jan me and my husband had intercourse and no protection the day after my merian cam out. and i have had a period since i took a test it said neg.I also have PCOS so before i even got prego with my last baby i never had regular periods. so what i am asking should i be worried im pregnant