CONGRATS on your pregnancy! I am 5 weeks pregnant too! Also on remicade. This is my 3rd remicade baby. YES - you CAN breastfeed on remicade. In basic terms the remicade molecule is thought to be too large to pass through to the milk. I have breastfed both of my kids while on remicade 10mg/kg every 6 weeks. They are healthy kids. Dr. Thomas Hale, leading expert in medications and mother's milk says this:
Based on this information, I feel perfectly comfortable nursing my babies while taking remicade. My oldest just turned 4 and she's an intelligent, healthy kid. So, I would tell you to go for it.
Feel free to ask more questions if you want. I'm no expert, but I've been-there/done-that, so I'm happy to share my experiences.