I read your post and smiled because the same thing happened to me, we were not trying to have a baby and one month I missed a period (very abnormal for me) but I didn’t think much of it because sometimes it happens right? Then I started getting nauseous every day for a week (again, very abnormal for me) and I knew something was up. We bought a two pack home tester and took both over the span of 3 days, both negative. Couple of days later no period still plenty of nausea, so I went to the doc, blood test came back neg. and the doc said well sometimes this happens. A week goes by and still no period and lots of nausea (running to the bathroom at the scent of any food with any sort of flavor) and we went all out, we bought every brand of test at the pharmacy and took them all one by one over the next couple of days, (at this point im almost 2 months late) a couple of days after the marathon of peeing on sticks I had one more (generic brand) test left over, was convinced (ha ha) I wasn’t preg but decided to go ahead and take it anyway and lo and behold, a positive, a blood test a couple of days later confirmed it. I don’t have much advice for you really but sometimes like other posters have said it can take a while for your hormones to get high enough for the tests to detect. Defiantly go to your doc if you miss another period but don’t be too surprised if you find a positive on that stick soon.