Do you think it's cold feet? It's normally to feel scared at such a potential life change.
Was the pregnancy planned? Or were you lapse with contraceptive as you thought it would be difficult/impossible to conceive?
You can still travel and have a career with children. It's even easier with just the one.
I'd delay and give yourself more time to think about it and discuss it with your husband. It might be that there's a bigger conversation to be had been you about what you want your futures to look like, both individually and together.
I'd also be realistic about how much travelling you're likely to be doing whilst covid is going on too.
I think 30 is a great age to have a baby. You've got your career established so it's easy to take a year out and go back in at the same level. You're also still quite young so once your child has grown up and left home to still be able to do what you want with your life.