Justifiably Worried

So today I called my doctor's office for my bloodwork results, and got a call back from the nurse.

Apparently my doctor said today that my HCG levels on my Saturday blood-draw were low for how far along I should be (I won't get the actual numbers until I pick up the summary this afternoon.)

In the meantime...

Commence panicking.

At the same time, I was really only guessing that I ovulated around CD30-31. I thought the line was getting a little darker on my OPK on CD29, but I have no way of knowing if I would have ovulated right after that, because I stopped using OPK's.

So really I suppose I was only guessing that I was 4w3d on Saturday, and could have been less far along than I thought. When I got my BFP (big fat positive) last Tuesday, I could have only been 9 or 10 dpo (days past ovulation, sorry for all the jargon, Liz!) rather than 13 like I thought. Which, to me would explain the lower numbers. (See how I'm trying to reassure myself?)

I'm trying so hard to not freak out, but when the nurse says things like, "The doctor wants you to come in today at 1:15 for an ultrasound to check for viability or an ectopic pregnancy..." you tend to die a little inside, I'm not going to lie.

Why, oh why, do they have to assume everything is wrong, and not FIRST assume that maybe I'm just not as far along as I thought?

So, point is, any thoughts and prayers for this afternoon's u/s would be much appreciated!