How do I know if my cramps are normal??

We have been ttc for 4 1/2 years now and had miscarriage two years ago. I remember a lot of cramping last time and this time I'm having a lot of it too. Nothing unbearable but it just seems abnormal to me. I'm 4 weeks 3 days and have both pcos and endometriosis and got pregnant on letrazole. I woke up in the middle of the night to cramps which feel like hard pinching.. I'm used to getting severe cramps during my cycle every month so I have no idea what are considered normal for pregnancy! Also have some lower back pain. No spotting or bleeding and want it to stay that way sooo bad!! Anyone else cramping more than they think they should?!