Strange period, could i be pregnant??

My periods are normaly fine no problems (I have PCOS and on metformin) my periods are 30-44days & my luteal phase is 15 day , but this month was weird spotted on wednesday then thursday spotted til 3.30pm then light/medium flow which lasted til 8pm, a few cramps but nothing to bad, then friday spotting with stringy CM. This is very strange for me as im medium/heavy flow for 2-3 days then the last day spotting/light. So i dont know what's going on. Over the last few days i've been feeling fatigue, change in smells, appetite has changed (want sweet things), cramping every so often, i pee i go for #2 (diarrhoea which i have had for 3 weeks), dizzy spells, dreams, pain in . Have done HPT which was negative this morning.The spotting/light flow was red/redish, CM somtimes there & sometimes not, but when i check my CP, i get a blob of EW on my finger tip. Any advice, no time wasters please!!!