TMI my 1st pregnancy

Okay im 7 weeks n 4 days pregnant and im worried i already have had an ultrasound at 6 weeks they said the baby was healthy and heartbeat was 110 . Im worried because im constipated and i can sometimes use the restroom and other times its like i cant and my stomach it feels like light cramps when you normally cant poop but it doesnt hurt and i dont wanna strain myself because what if that hurts the baby i was wondering could i have a miscarriage due to me being constipated im worried