I hope that this is not your main concern during this time and are interested in the stages and development of your offspring, so here's a link that will take you to where you answers will probably be better answered, except for the clinician visit of course.
If he/she forbids intercouse during the pregnancy it is for a reason...
http://www.babyfit.com **This one is free to join and has it's own forum. Also covers other questions you might have, diet, exercise, medication and clinical procedures.and sex. etc. This also has good illustrations showing you the different stages, and might be fun for both of you to check out.
Happy parenting.
Also, your wife might be a little reluctant to refuse to have intercousre with you right after birth, but there is a reason for waiting at least 6 weeks, due to the pain, healing process, and threat of infection, and just plain respect, so please keep that in mind as well. Also because at that time she's very firtile again. So at that time it's best to take things into 'your own hands' so to speak.