If you throw up less than 2 hours after you take your pill, it is considered a missed dose. But, the next step depends on which pill you threw up. “Missing a pill” when taking combination pills means missing the normal time you take it by 24 hours or more, so you still have time to take another pill. If you miss two combination pills, then you should use back-up protection, like a condom, for seven days. Progestin-only pills (POP) contain no estrogen and a lower amount of progestin, so even missing one pill means you should use back-up protection for at least two days.