It's normal as long as you aren't bleeding. Your body is getting use to being pregnant and your uterus is stretching. Drink lots of water. It should help ease the cramping.
It is common. I cramped early in my pregnancy and it scared me. I am not 16 weeks and baby is doing great!
I had these two symptoms as well . Was feeling thirsty n drank a lot. Am now far better. Wonder i haven't experienced any nausea n vomiting. Am 8 was 5days