Hi Shjimani,
Because thal intermedias carry two defective beta globin genes, all children you have will be thal minors. They will receive one thal gene from you and one normal gene from the father. So, your child's health will not be like yours and will be much closer to normal. There are procedures that can tell you your child's mutation before birth, but is doesn't seem necessary, since it takes two mutations to cause intermedia or major.
As far as pregnancy, you should be on folic acid already and if you aren't, you should start before trying to become pregnant, as this greatly reduces the chances of birth defects and is also a requirement for building red blood cells, and should always be taken when a patient is on hydroxyurea, along with magnesium and L-carnitine supplements, as these all work together to enhance the effect of hydroxyurea.