After i stopped taking bc pills my period is irregular, last month it lasted for 2 weeks, and now 1.5 weeks of brown/pink spotting. what should i do?

Wait a while.: BC pills basically shut down your natural hormonal cycles and it may take a while for them to "wake up" again once you stop them. Usually your cycles return to the way they were within 3 months of stopping them. If you continue to have irregular cycles for another couple of months, you should check with your doctor. You could do a pregnancy test, but you don't need to do anything else for now.