18 weeks pregnant not showing

Hi everyone, my name is Brooke and I am 18 weeks pregnant. Before I got pregnant I gained thirty pounds up to 160 in a few months because of this birth control I was on (I think it's why I've been losing so fast). I weighed something like 164 when I found out I was pregnant, but lately I have been losing weight at a rapid pace. I am down to 154 and am steadily losing weight. I've only had one doctors appointment and one ultrasound and they said weight loss in the first trimester is normal, and I had been having extreme food aversion problems too.
In my first trimester I threw up every single day, at least four times, but it has since calmed down to maybe 3 times a week. Still, I have no belly (besides the fatty one ;P) and only feel this crappy morning sickness every day to remind me I'm pregnant, but it's all I've got.
My last doctors appointment was on July 14th where I saw the baby- the heartbeat was good, and my urine showed that the baby and I were getting all the nutrients we needed (but I was only eating about one meal a day o.O) and it was very awake and kicking!
I go back on the 11th and was wondering if my concerns are valid.
Also, I was examining my breast in the mirror, feeling mammary glands grow, etc, when I guess I mashed on it too hard and some clear liquid came out. That was pretty exciting, but now I'll feel a little wet spot every now and then in my bra from the same breast, is that normal?

Ahh thanks so much!

-edit-
Also! I've been feeling something like I think contractions feel like? I thought I was about to have a miscarriage a couple of times because throughout my whole pregnancy I've been having severe.. period cramps. I had problems with my period before my pregnancy; it was suspected endymetriosis. Are these period cramps normal? They aren't disabling me and knocking me to the floor but I have to sit down and do some deep breathing when they hit.