What Do This BMI Indicate During Pregnancy?

I am in 30th week of my pregnancy and i am working. I have to walk nearly 1 km per day. some day with a laptop. According to my medical records i don t have pressure and as per the OGTC test i am with in the expected limits. My BMI is 18.5-24.9.I just want to know my travailing and carrying laptop will badly effect to my baby in this period?