Ella, Plan B and other morning after pillsOnce upon a time, all women had by way of emergency birth control was an off-label use of a high-dose oral contraceptive (think: two doses of Ovral, followed 12 hours later by another two doses of Ovral), says Dr. Lissa Rankin, a San Francisco OB-GYN and author of "What's Up Down There? Questions You'd Only Ask Your Gynecologist If She Was Your Best Friend."

The problem was that such a high dose of estrogen made women want to hurl, literally, and then they were back to square one. Enter Plan B, the morning after pill that could prevent pregnancy three days post-intercourse, which utilized higher doses of progesterone, minus the estrogen, so that side effects were significantly reduced.

And now, a Food and Drug Administration advisory panel is meeting to discuss the approval of an emergency contraceptive pill already sold in 22 European countries that works five days out, dubbed "Ella." With all of the choices, here's how to pick a just-in-case contraceptive that's right for you.

Morning After Pill #1: Plan B, or Next Choice
Use It When: You know right away that you've slipped up, says Dr. Rankin. The first dose of Plan B, which consists of Levonorgestrel 0.75mg, must be taken within 72 hours of unprotected sex. Then you pop the second pill 12 hours later. This OTC option is also easier for progesterone-sensitive women to stomach.
Pros: Since Plan B is no longer under patent and Next Choice is available as a generic, both tend to be the budget choice.
Cons: Timing is everything with this option. You have to remember to take one pill (within 24 hours of intercourse for greatest effectiveness) ... and then the next exactly 12 hours later.

Morning After Pill #2: Plan B One-Step
Use It When: You've had unprotected sex within 72 hours. Consisting of Levonorgestrel 1.5mg, this OTC emergency contraceptive is taken in one dose.
Pros: "The advantage to Plan B One Step is that you don't have to remember to take that pesky second dose exactly 12 hours later," says Rankin
Cons: Queasiness. Side effects like nausea and vomiting are a risk of all emergency contraceptives, but since this pill is infused with more active ingredients, the risk is higher.

Morning After Pill #3: "Ella"
Use It When: You make a boo-boo in bed, and it slips your mind to race to the drugstore for Plan B right away, says Rankin.
Pros: Packed with the progesterone-moderating ingredient Ulipristal Acetate, Ella has been shown to prevent baby-creation for up to 120 hours -- two days longer than Plan B or Next Choice.
Cons: It's not available in United States ... yet. And if given the green light by the FDA, it would be doled out by prescription only. Plus, users could expect pushback by anti-abortion groups who say that Ella is a chemical cousin to the abortion pill, RU-486 (mifepristone).

Have you ever resorted to taking a morning after pill? What happened, and how did it work? Pick an anonymous handle and tell us in the comments.