Weight...

Sharel • Married since December 14, 2014.
I'm almost in my 2nd trimester and I haven't gained any weight. I started at 135lbs and now today I'm down to 128.5lbs at 12+4 weeks. I feel like I'm wasting away. I usually don't throw up what I eat, just in the morning. I know it isn't a huge weight loss, but I feel like it is and I'm worried about my health and the babies health. It's hard for me to take prenatals, but I'm trying the best I can. I don't know what to do...