I'm almost 7 weeks and I've had back pain the entire time with cramps mostly the first 5 weeks. They weren't very intense though. At first they felt like menstrual cramps and now they come and go but aren't very strong at all. Ask your doctor you should have an appointment soon!
I've had BAD cramps almost the entire time I've been pregnant so far (6 weeks). I've also been to the ER multiple times because of the cramps. Every time I've gone with this scare fortunatley I've been reassured with rising hcg levels and progressing baby on ultrasound proving, these cramps must be normal.