Cramps…

So about how long should I experience cramps in first trimester? I read an insight on here saying that it can be caused by growing baby, gas, bloating or constipation. This is my first pregnancy so I'm kinda nervous. They're not too bad it's just I keep having them, they'll last about 7 seconds and stop. Should I be worried or is it normal? I wanna make sure my baby is okay and that I'm not overreacting 😕