What is wrong with me?

It’s been 12+ months since we’ve been actively ttc. Last week I had a vaginal and internal scan to see if I had anything wrong with me and everything was fine. My last period was the 16th January and this morning I woke up bleeding with period symptoms, I don’t know if it’s my body adjusting still as I’m 19 or I don’t know if it’s pregnancy or something wrong. The scan didn’t show anything wrong with me though and the nurse said I was still able to have children but I’m confused because I don’t normally get periods regular I’m normally always late. My cycle lasted 19 days shorter than usual, could there possibly still be something wrong? Any advice would help