Thanks for posting your query.
You are 2 months pregnant.
If your cycles were regular and 28 day a cycle and if your first day of your LMP is the date you mentioned then your conception date would be 1/8/2011.
Since ovulation usually occurs on 14th day of a cycle.
Regarding sexual intercourse first 3 months and last three months of pregnancy
you need to be cautious in the sense the strokes should be smooth and in last three months you can involve in act by you being on top of your husband and your husband being in the bottom.
Hope I have answered your query.
Wishing you good health.