light period or pregnant??

Ok so I’ve had my mirena for 2.5 yrs now and I have really experienced it all period wise. I had every few months to no period for 8 months, but for the past 1.5 yrs ish i’ve had a pretty consistent moderate flow 7 day period. In Dec. I had unprotected sex with my bf and january my period was kinda wonky and light and this month i’ve essentially had spotting BUT during the time i would have my period normally. Should i be concerned or no? Also side note, I graduated college and moved at the end of jan and also started taking iron pills regularly before my jan period. am i just ~unbalanced~ ?