Job application while pregnant

Hello, just want to ask your opinion so i have this job offer and i am 4 months pregnant. My interview was on july and just knew im pregnant last sept. Should i just tell the hr that i am pregnant before signing the offer? But they do not ask if i am pregnant or not. Also not sure if they will cancel the offer if they found out im pregnant? Work from home. Im an It consultant. Dont need to travel at all.