Yes, this could be perfectly normal.  I found that I felt like I was premenstrual during the early weeks, and part of that for me is lower back pain.

Congratulations on your successful pregnancy attempt.

Hi there,

Firstly congratulations on the pregnancy. I don't think your back ache would have anything to do with the pregnancy since you are only 5 weeks along and the baby is probably only the size of a jelly bean. Have you done anything different in the last few days? Lifted anything that was abit heavy? Or have you spent alot of time sitting down today or yesterday?

I wouldn't stress too much unless the pain becomes unbearable. Try a warm bath or a heat pack on the area and see if that helps.

Good Luck

Juzzy xoxoxoox