3 weeks?

Did anyone else find out at 3 weeks? My period isn’t supposed to start until the 15th, however I was feeling sick this weekend and went to urgent care. The lady asked me if I could be pregnant. I told her yes, because my husband and i have been trying but wasnt due for a period yet so I didn’t test. She did a urine test and it came back positive! So she did a blood test which came back positive. So she wanted to do an ultrasound to make sure everything looked okay. She said I’m like 3 weeks and that’s why she couldnt see a sac yet. Anyone else experience this?