Is going back and forth between constipation and diarrhea a sign of early pregnancy?

While I'm not ttc, I havent been actively preventing it. Me and my boyfriend have been together a year and a half and we always have unprotected sex. For a little over a week now, Ive been feeling pretty strange. Unusually tired, cramping and pulling sensations in my lower abdomen, gas, and my breasts are super sore... My period is late but as a woman with PCOS, I never take that extremely seriously... my real question is I have been going back and forth between having diarrhea and being constipated ALL week. Is that an early sign of pregnancy?