Postpartum sex is different for every woman who has given birth, and even from pregnancy to pregnancy. Of course, what sex will feel like depends on how soon you try to do it, and on the events during your birth. If you feel anxious, and kind of like a virgin again, you wouldn't be the first. We recommend that you approach doing the deed much like you would if you were a virgin: go slowly and stop if it hurts. Take your time to engage in plenty of foreplay and don't expect to necessarily have intercourse the first time you are intimate (OK, maybe that is not what it was like when you had sex for the first time ;)).
Most OBGYNs would advise you to wait for around six weeks, when your body has recovered from childbirth and any tears or episiotomy you had have healed. At that time, that nasty lochia (postpartum bleeding) will probably also have come to an end. Still, the first time is likely to be a little uncomfortable, not in the least due to the fact that you have a newborn who can wake up at any time. Then, there are engorged breasts that can "explode". Men may feel a difference in vaginal tightness, but not necessarily. If you received stitches after birth, you may even be tighter than you were before. If sex is painful and continues to be so, do contact your doctor about a solution to that problem and do not suffer in silence.