Soo i have irregular periods 90 day cycles...

This is weird for me i have been spotting for 2 weeks now. I usually dont i got my normal period on dec 5-13 and had sex the 13. Usually i have 90 days after then i spot for 2 days every 12 days or so. So this is just weird for me i was wondering if anyone else has experienced this i dont understand why i have been spotting for so long gahhh. Its annoying ive been thinking im pregnant you know like i have experienced nausea, been overly tired,heightened smell and somewhat bloated idkk what to think helpp. Probably going to get a prego test today and test in the morning thanks for reading:)