Diarrhea as a pregnancy symptom?

I have IBS with chronic constipation and I normall have to take a pill every day o be able to have a BM. And literally, if I miss a day, I don't poo. I stopped taking it on Thursday since hubby and I are TTC and today and yesterday I have had some bad gas and diarrhea. I'm 7DPO and I have been spotting brown blood since yesterday as well. Anyone have experience with this?