MAP Side Effects after a month?

I’ve taken Plan B on April 28th, 12 hrs after intercourse (protected but I felt like the condom slipped so I took the pill the next day). I bled like my period 5 days earlier (May 9th) than when I’m supposed to. On May 18th, I visited a doctor and she said she doesn’t think I’m pregnant, and ordered a transvaginal ultrasound. She said my uterine lining is very thin and there’s no sign of pregnancy (I would’ve been 5 weeks along during this time, as I’ve had my period for April on the 12th). I did not take any other test anymore. Now, roughly 12 days before my period starts, I’m experiencing lower back aches and tender breasts. Also been hungry a lot. I am not sure if these are still due to the pill, or PMS? I think it’s a bit early for PMS... should I still take a test? I can’t help but overthink :/