Can diarrhea really be a pregnancy symptom?

So today I'm on cd 36. I've been having diarrhea for almost a full week now. In the beginning it was coupled with bad cramps like AF was coming, but hasn't yet. I tested a few days a go and it was negative, so I thought I maybe had a stomach bug. But I've been googling (probably way too much) and diarrhea can be a early pregnancy symptom. Oh yeah forgot to mention the daily head aches. But I do have PCOS, so I guess it could be nothing??? TTC #2 (for almost 3 years now 😬😕)