Like any medication, emergency contraceptive pills can cause side effects, such as nausea or vomiting, your period may come earlier or later and be heavier or lighter than normal. If you get especially sick, which is rare, ask your doc about medications that help with motion sickness. You’ll need to keep the pills down for them to be effective.

In some states, you must get a prescription from your doctor or a clinic like Planned Parenthood. In others, you can get the pills directly from a pharmacist. To find out which pharmacies or doctors provide emergency contraceptives, visit www.not-2-late.com.

3. Get tested.
Even though the guy likely assured you he’s been tested for everything under the sun and he’s clean, get checked anyway. Minkin says you don’t have to run out and get tested the next day (some infections don’t show up that soon), but definitely go within a week or two. When you get there, be specific. You need to be clear about how well you knew your partner’s sexual history so a doctor knows what to test you for.

4. Get retested.
“It’s a possibility that you may have become infected [with an STD] and it would not be picked up immediately after the condom broke,” says Hutcherson. So, it’s a good idea to be retested within four-to-six weeks.

“Six weeks later will cover everything except HIV,” Minkin says. It can take the body up to six months to produce HIV antibodies of detectable levels, so get retested for HIV in three months and again at the six-month mark.

5. Prevent it next time.
If you’re in the clear this time, here’s what you need to do to prevent future condom slip-ups: