Ladies please help!!

I have no idea what’s going on with my body I have gotten multiple faint lines on 4 different FRER and even the cheapies from amazon, these were taken from the 25th-31st and now I’m just getting BFN! I still have extremely sore breasts (nipple area) and awful nausea and heartburn, I’ve been pregnant twice before and feel the same way I did previously. I don’t know what else to do/think. I have pcos so I have no idea when my last cycle was , I do still ovulate every month my last positive was on November 16th and I didn’t track December since I was away on a cruise for two weeks. Is it all in my head? I need some advice ladies please