is it normal to have a huge weight gain in the first trimester?

This is not normal at all women to be healthy should only gain 25 to 35 lbs of weight in an entire pregnancy.  Since you can't take back the weight gain. Start eating healthy drink plenty of water and maybe do some light excercise you can start walking, and light cardio, also you can swim, there are other excersises you can do during pregnancy. Start trying to gain in moderation, any extra weight you put on that is not contributed to baby is weight you have extra after baby is born. Also gaining to much weight can be unhealthy for you and for the baby. See your doctor there could be another reason for your weight gain and if need be start seeing a nutritionist. And lastly please eat healthy if not for yourself then for your baby. I am 7 1/2 weeks pregnant to and haven't gained any weight, my sister lost weight in her first trimester.

Every pregnancy is different. During my first trimester i gained 15 lbs. Then my 2nd tri came and I lost it all plus some (but I also had "morning sickness 2-3 times a day). I started to gain weight again about 2 weeks ago. I am now 26 weeks. If you or your doctor have serious concerns about your weight gain, try to meet with a nutritionist for assistance with meal planning.

I am also 7 1/2 weeks pregnant with my second child, and I'd say in about 2 more weeks I'll need maternity clothes! I'm right there with you momma. There is no such thing as "normal" in a pregnancy. But if you're worried about it being healthy, I'd say just eat healthier.