Is having sex safe during the first trimester?

Carina • 25 years young. baby #1 born April 11th 2017❤️
Okay this might sound stupid but my hubby has a very large baby making tool👶🍆 and every time we have sex (now that I'm pregnant) it hurts!! I'm almost 4 weeks and I want this peanut to stick so I don't want to take any chances😞😢😩?? We just did the deed and I'm crying of how bad my cramps got right after..