Brown Spotting

Hello everyone. I have missed my period, was suppose to happen February 26th. we have been TTC for awhile now. I have pcos and hypothyroidism so we have had lots of negative tests. I have been spotting brown though since Saturday. Not sure if it's possible I might be pregnant *be so thrilled we are buying a house right now so it would be perfect*. Had sex 3 days on my fertile days so I guess it could be possible. Should I take a test??