Trying to concieve with pcos

Hi. Me and my fiancé have been TTC for a year now, about 6 months ago I was diagnosed with PCOS. However, I've been taking 1500mg of Metformin every day since. My periods are irregular, but always EARLY. Never more than 1/2 days late. I'm currently 11 days late, which is odd for me. I'm SUPER TIRED all the time!! And for the past few days I've had such agony in my boobs and nipples are so sore and tender!! I feel twitches in my lower stomach. The day I was due on this month, I thought AF had arrived. I was spotting very pink (not a lot) early on the morning, and a few hours later it had completely stopped. I've done 4 tests spread out across the 11 days I'm late and all negative!!! Could I be pregnant or not? It's driving me mad  sorry for long post!