How do I deal with my grandpa judging me for getting pregnant?

Ask him how he felt when he was pregnant with your mother.

Visit the Assassination Station!

you tell him you dont care what he thinks

are you married , are you over 18 or still in school !! admit one thing a naked woman isnt the best to look at especially there furry bit , are they ..or how about the sagging boobs or the fat butt ..

Unplug that machine with the annoying beeping

ask him how the f*ck he was created

so what happened was your grandpa was upset he wasnt the pregnant one 

Point out to him that he comes from a long line of people who had sex with each other, and he's continued that line by having sex.

He's entitled to his thoughts, but they aren't about you... they are about him. 

Tell him that's what women are for.