Is lower back aches without cramping normal in early pregnancy?

I have just recently found out I am pregnant I am about 5 and a half weeks. I had a miscarriage 10months ago at 7 weeks started spotting at 6weeks and we decided to take some time off as I was still trying to deal with it. We decided to start in the new year and in the first month of trying we got a BFP! We are very excited I have so far had a lot different experience with this one vs the last. I do not have any cramping I had AF type cramps for about 2 days but now I just have lower back aching if i stand too long or sit too long. Is this normal? With the miscarriage I had really bad cramps like period cramps, bad back pain that got worse and then spotting started. I want to think positive and I have done very well in thinking positive but like a lot of other women i can't keep my mind away from will it happen again. Please let me know if this is very normal in early pregnancy??? Also when normally does morning sickness start as I have not had any yet??