It is now well recognised and accepted that making love throughout pregnancy is perfectly safe, in the absence of pregnancy complications such as
heavy vaginal bleeding or the waters (amniotic fluid around the baby) being broken.
During the first 12 weeks or so, some couples will feel so excited and elated about their new pregnancy that sex becomes an intimate celebration of this event. This can be especially so if it has taken you a few menstrual cycles (or fertility treatments) to conceive your baby (or the pressure is off to 'perform' to a schedule). Or it may just be a pleasant surprise!
However, for many women the 1st trimester of their pregnancy also brings with it many physical changes and discomforts such as continual tiredness, nausea and/or vomiting, making their desire to want to have sex wane. This can sometimes be compounded by feelings of being unsure about the pregnancy and/or how her partner is reacting to news. Another child (or children), a demanding job and/or hectic life schedule can also mean that sex takes a back seat for a while. Try to be patient with each other at this time and be honest with how you are feeling about the pregnancy and having sex. Cuddling and reassuring each other of your love through this often tumultuous time of psychological adjustment can help keep you close until you are feeling more inclined.
For many couples, sex during early pregnancy also bring up concerns about miscarriage, especially if the woman has had a miscarriage in the past. It is now recognised that penetrative sex during early pregnancy does not cause miscarriage, and if a miscarriage is going to occur, it will do so whether the couple have sex beforehand or not.
However, even with this in mind it is still important to follow your own instincts and do what feels right for you.