Worried

Eva • My husband and I have a son who is 3 (10/5/15) and a daughter who is 1 (11/30/18) and we just found out we are expecting again!
Well I was able to find a pulse with my fetal Doppler a couple days ago, but today I couldn't find anything...I know I shouldn't worry because I am only 10 weeks and 5 days but I was so excited to hear it again. I guess I'm just disappointed that I couldn't and so worried that something may be wrong. My next appt isn't until April 1, I'll be almost 13 weeks by then! Just seems so far away! I hope everything is okay...