Twins??

Hello all! I will be a first time mom and I recently found out I was pregnant. I went to the emergency room with cramping and bloating and the doctors estimate me to be about four weeks. They performed a transvaginal ultrasound and there were two gestational sacs visible but they say that I’m too early to see anything inside of the sacs. My hCG levels were in the high 700s. I know I can’t know for certain until I get an ultrasounds further along but I’m paranoid. Any tips or similar situations? Thank you in advance!