Is this normal for 4 1/2 weeks pregnant?

I Know 4 1/2 weeks is very early for any symptoms but I have been experiencing all kinds of symptoms since I was 2 DPO. Just wanted to make sure that mild cramping at this time is normal. I have been experiencing period like cramps all day (they come and go) also my back is hurting a bit. I believe the backache is from my that I sware have gone up a cup size in the past week lol....