Will this bad flu still be around and so dangerous this summer?

I’m 12+3 weeks pregnant, have 6 kids and live in Germany. I’ve had the flu shot but no one else in my household has. We have relatives coming to visit this summer from the states. They’ll be here for a whole month and leave just 3 weeks before my due date. I’m super worried that going through international airports, someone might bring the nasty flu that’s going around in the states right now, here. Am

I over reacting? Should I get my hubby and the other kids the flu shot too? What if my relatives don’t get the flu shot? I just can’t have the flu when I’m about to give birth! And I can’t bring a newborn home if anyone in my house has it. How long after our relatives leave will we know the incubation period is over? Any advice is appreciated. Thanks!