There is, surely, a good time (OK, OK, no such thing as a good time for this. Less bad? Hideous-but-doable?) to get a stomach bug.
I contend that it is not during a violently painful period (thanks, adenomyosis!), when your very ability to stand up and stay conscious depends on keeping your cocodamol tablets in your stomach long enough to digest them.
Also, the hurling action has a deleterious effect on the irritable uterus.
I am not having a good day.