First u/s tomorrow at 7(?) weeks...so scared something will be wrong!

j&mmadison

I have my first u/s tomorrow...I just got my bfp on Monday and due to such irregular cycles they scheduled the u/s right away to see how far along I am.  Last af was mid-may, but I have no idea when I ovulated since then. I *think* I am about 7 weeks though. Anyhow...I am so scared that I won't see a sac or heartbeat or something will be wrong!!  I will feel so much better after tomorrow.