So FIL calls me today to let me know he was just diagnosed with whooping cough

I'm 36+4 pregnant, and DS is 16months, and we have fairly regular contact with the ILs, well when they have time for us anyway , but we seen FIL 3 times this past week. Who knows how long he has had it, and generally speaking you're considered infectious for the first 3weeks if not treated early

DS has been cranky the past couple of days and developed a bit of a cough yesterday after waking up with a snotty nose... please we don't get it