Look morning sickness happens for a reason and its to protect the unborn baby. While you have morning sickness you do not feel like any caffeine products, alcohol etc and this is while the baby is developing in its first stages of life which is very critical to having a healthy baby. When I was pregnant I did not want to have sex for the first 3 months after I got pregnant due to dam morning sickness which I would get morning, noon and night. But once I was over it the hormones kick in (second trimester) and you are so incredibly horny its unbelieveable.