I am 17 weeks and I too can't sleep .. my problem is from anxiety though because I lost my last two babies at 20 and 24 weeks. It's safe to take benedryl to help you sleep. I do from time to time when I really really need to sleep!
Talk to your dr about what you can take to sleep. Mine gave me sleeping pills. I take hald of one and sleep so well. Don't take them every night just if I haven't slept well for a few nights I will take one.. your dr might give you something and its worth asking them about it.
I definitely understand the sleep deprivation. It really ***** :( I work overnights and have a terrible time trying to sleep during the morning/afternoons. Im also up every hour, or hour and a half, then still manage to work/do things around the house. I always thought the 2nd trimester was supposed to be the best, sure i dont feel sick anymore, but this has been brutal for sleep.
Thats exciting about your ultrasound coming up, and really exciting that you are not finding out the gender! I was mixed on finding out but my bf wants to know and he wouldnt be able to keep it a secret from me! lol