If you have not entered menopause yet, there is still a possibility of becoming pregnant, although relatively slim. Most women that age would need some serious medical intervention to become pregnant, but it's not impossible at all. If you are still having regular menstrual cycles, count down 28 days from the start day of the last one. You should be at least a week overdue from that day to determine pregnancy, although for some women it can take longer. Some women need to miss their cycle for a month to realize that they are pregnant. At this point, if you think it's a possibility, the only thing you can do is wait, assuming you have not missed a cycle for a longer amount of time. Dizziness and queasiness can have other contributing factors as well, so if you are not pregnant, you should still see a doctor to find out the cause of the symptoms. I think this article may be interesting to you.