9 weeks, no baby in ultrasound, a little scared

Sophia • 23, newlywed usaf wife at a new base, and first time expectant mommy!
I'm supposedly 9 weeks in and just had my first ultrasound today. I was told by the tech that she didn't see a baby at all, but my pregnancy tests are all positive. I was told that it could still be too soon and that my weeks could be off. Took a blood test today but won't find anything out til Monday which seems forever to me. Is this normal? Has this happened to any of you? I'm trying hard not to worry too much but it's difficult. 😔 prayers please.