Advice needed!

I am 20 year old woman and I need advice. I went to the doctor a few days ago, and upon doing a physical, she found something. When she pressed on my stomach, it was super firm and uncomfortable. It was almost as if it were a mass, she said. I’m not pregnant, I’ve had regular cycles, and those are heavy. I don’t know what’s happening and I’m scared.

For the last couple days, I’ve had pain beneath my belly button/lower abdomen. I could have had pain before, and I didn’t notice (there could’ve been pain I brushed off as nothing). I have an ultrasound coming up, and I’m extremely nervous. I’ve never even had a pap smear. Please help!

(I don’t know who else to talk to. I’m in an isolating situation and I just need some help. Thank you!)