2 Answers

A recent study by the American College of Obstetricians and Gynecologists shows that intercourse after 29 weeks does not increase a woman's risk for preterm labor (assuming that the pregnancy is a normal one).

http://www.parents.com/pregnancy/my-life/sex-relationship/how-much-sex-during-pregnancy/

  It is usually perfectly safe for couples to enjoy a sexual relationship throughout pregnancy. In fact, a healthy sex life is positively beneficial, because as well as maintaining your relationship with your partner, it helps you to unwind, reminds you that you are a sensual woman as well as a mother-to-be, and it can also be a good form of exercise. Sexual intercourse cannot hurt your baby who is safely cushioned in a bag of fluid within your womb; even deep penetration is not harmful.

  You may be advised not to have sex if you have a history of miscarriage or premature labours. It may also be sensible to avoid intercourse if there is unexplained bleeding, and after your waters have broken. Sex is also not advised in cases of placenta praevia, or where the placenta has partially dislodged itself from the womb wall, because penetration could increase the risk of bleeding.

http://www.mothersbliss.co.uk/nine/sex.asp#goodidea

If it is physically possible, go for it with the above guidelines of safety!  It also helps to maintain the pair bond relationship...