Accepted (verbally) a postdoc position and found out I'm pregnant the next day

I verbally accepted a postdoc position in another country and literally on the next day found out I'm pregnant. The contrast is for 2 years and the PI made it clear they want certain amount of output by the end of that term. I am currently conflicted, I have not received or reviewed the final offer yet and I'm not sure what to do. I don't want to show up 4-5 months pregnant and inform them that I will be going on a 4-month maternity leave shortly. In addition, pregnancy may prevent me (maybe) from some of the lab work (but most of it I will still be able to do). I'm stressed out about the logistics of it, too, but also that I'm going to let my PI down because of my leave and because when I was pregnant with my first, my productivity was way down. What would you do in my situation?