Sore nipples

I am on depo and a few days ago , maybe a week I had some spotting and thought it was IB and I took a test it was negative , I’ve had sore boobs for 3-4 days now and they are just pointy and then go soft for a while.

Could I be pregnant or could it just be the depo shot ?

I get my shot every 3 months exactly and my period was supposed to get here tomorrow but I don’t know the accuracy.