Sex in pregnancy is almost always safe and may even be your hottest sex ever. Keep these guidelines in mind and enjoy!.Some of life's great pleasures are restricted or outright banned during pregnancy.But at least one pleasure of the carnal variety is still there for the enjoying all 9 months of your pregnancy.Here's what you need to know about sex in pregnancy so you can keep it hot all gestation long.Get into Position "Any sex position you usually enjoy will still be comfortable during the first trimester," says Hilda Hutcherson, M.D., a clinical professor of obstetrics and gynecology at Columbia University College of Physicians and Surgeons in New York City. "But by the second and third trimesters, many women find intercourse while lying their side is the most comfortable. It takes pressure off uterus and it takes less energy for mom-to-be." Another pro-uterus position: Doggy style. "This allows for deeper penetration, however, which some expectant women might find uncomfortable," she says. (Discover 6 hot sex positions during pregnancy.)Be Prepared for Amped Up Excitement We all know that the classic first-trimester symptoms -- the constant need to pee, feeling tired and nauseated, and having sore boobs -- are anything but sexy. The good news? By trimester number two, many of those un-sexy symptoms fade while a key frisky one kicks in. "Being pregnant increases blood flow to the pelvis and genitals, which can leave some women with a constant feeling of arousal," says Dr. Hutcherson. In fact, women gain 3 pounds of blood during pregnancy and most of that flow strikes below the belt, according to the March of Dimes. Because of all that blood and engorgement, "many women experience their their first --and even multiple--orgasms at this time,” notes Dr. Hutcherson.Protect Against Premature Labor Sexual activity during weeks 29 to 36 of pregnancy doesn't up a women's risk of premature delivery. In fact, women who are sexually active late in pregnancy are less likely to deliver before 37 weeks than their sex-avoiding pregnant counterparts, according to a study in the journal Obstetrics and Gynecology.Don't Shy Away From Receiving "Oral sex is totally safe during pregnancy," says Dr. Hutcherson. "It is recommended, however, that partners refrain from blowing air into the vagina because of risk of air embolus. That's when a bubble of air gets into your blood circulation. But why would anyone do that anyway?" Anal, on the other hand, may not be the best idea, since many pregnant women have to deal with hemorrhoids. Plus, anal sex just might allow infection-causing bacteria to go from the rectum to the vagina.Know When to Say "No Thanks" If you're refusing intercourse because you think it's harmful to your baby, think again. The fetus is well-protected by the amniotic sack, the mucus plug and by Mama's abdomen. You may be leery of sex, however, if your physician has deemed your pregnancy high-risk, for whatever reason. "Generally, doctors may advice against intercourse in the mom-to-be has a history of preterm labor, premature rupture of the membranes and/or preeclampsia," says Dr. Hutcherson. Leaking amniotic fluid or vaginal bleeding may also put the breaks on intercourse during pregnancy, according to the March of Dimes.Keep the Lube Handy Another sexual upshot of being pregnant: Many women experience extra vaginal discharge, making lube unnecessary. But if you do need added moisture, a "water-based lubricant is safe during pregnancy," assures Dr. Hutcherson. And thanks to your tightly-sealed cervix, there's no danger of lube migrating into your womb. So go ahead and get busy, Mama!