Possibly Pregnant at 53 Update?

I have been seeing a woman who is 53 and she has not had a period in 3 years because of menopause. We were recently intimate a week ago and she says that she feels nausea and the smell of food makes her want to vomit. This happened 3 - 4 days after we had sex. We took a pregnancy test but didn't do it right. Because its suppose to be done in the morning. It says she isn't pregnant and she wants to believe just that. She also doesn't feel as bad either. We don't know if maybe its her body reacting to having sex because of how long its been Nov. / Oct. and now its August. I feel that we should re-test because it had only been 9 days since we had sex before the test and we did it incorrectly. She says it doesn't matter. If she is pregnant then she is if not then so be it. We would just wait months and find out. The anxiety over this hasn't allowed me to really sleep or eat much because I am eager to know the truth. What should I do? Wait a month and try and talk her in to doing the test again or try and do it in another week?