5 weeks and 2 days pregnant

Today I’m 5weeks and 2 days pregnant. Last night I was in the emergency room because I could keep down any food yesterday. They did a bunch of blood work and an ultrasound. Apparently my HCG level is low at 107. With the ultrasound they couldn’t see anything in my uterus. She said I could be to early to tell on an ultrasound or it could be an ectopic. Is that normal for this early? Is the level too low?

The ER doctor wrote me a script to get another HCG blood work done on Monday to see if it’s risen any.

My OB can’t get me in until the 21 of May. Trying not to stress about this but I’m a little scared honestly. Should I contact my OB on Monday after my blood work and ask to be seen sooner?