You had 7 pregnancy tests and a period, and still think you are pregnant? This suggests an anxiety level not based on the realities of the situation. If something you have done has made you this obsessive, dial the activity back with the boyfriend until you are comfortable with whatever level of contact you and he are doing.
Really, this is not going to lead to pregnancy. You might here someone say there is a 'risk' but is it a true risk? As in will it happen? No. A penis needs to enter your vagina for pregnancy. Sperm is smart but not smart enough to find your vaginal opening and make it's way inside. You do not need pregnancy tests, you aren't pregnant. good luck