I'm not sure what answer you would like to hear but I too took the tricyclen and "messed up" my next pack start time and became pregnant when I least expected it.

I would wait a few days and try another home preg test. I have had three pregnancies and found home tests to be quite accurate very early on but not too early. If you get a negative result wait a few days and try again.

I found as well, that if you purchase the more costly home tests, they seem to be able to pick up the pregnancy hormone easier than the less expensive home tests. So, spend a few extra bucks. It may be worth it.

Like the last answer however, if you wait for a couple of weeks and no period and no positive test result on your home test then see your doctor for a blood test.