10 weeks, first OB appt at 12 weeks...

this is my 5th pregnancy, and I am currently 10 weeks along.
My first ended in a loss at 14 weeks, with hearing the heartbeat at my first OB appt at 10 weeks. My second pregnancy was a little over a year later, ending in the birth of my daughter (now 7). About 7 months after she was born I got pregnant again, ending in a loss at 12 weeks. That was in 2003. In Jan of 2010 I found out I was pregnant again, and lost it in Feb of 2010.

Following all of that, my doctor put me on Femara to help increase my chances of successful ovulation and pregnancy. After 2 cycles it worked and I am currently 10 weeks pregnant.

Symptom wise, I have all the symptoms that I had with my one successful pregnancy, and all of my lost ones had none of those (nausea, swelling feet, sore breasts, indigestion etc)So I feel pretty good about how this pregnancy is going for the most part.

The home test turned positive as soon as I used it, and I went to my doctor for a confirmation appointment at 6 weeks and all was still going well. My symptoms keep me pretty reassured as well, but having to wait until 12 weeks for my first real OB appointment has definitely got me biting my nails so to speak.

My husband is convinced that we're having twins.... he's basing it on gut feeling, the over-the-top symptoms that I am having, the amount that I'm showing already, the infertility drugs we used, etc.

I'm wondering myself honestly, and I know there's no concrete way to know for sure until my doctor says one way or the other, but I am wondering how possible it is?

Is there a chance we could be having twins? How would I be able to tell? Can I measure myself to tell?