The instructions say "as early as the first day of your missed period". My cycle is very irregular, usually 30-45 days but sometimes I can go months without getting my period. So how do I know when I can take the test and get an accurate result? It's been around 35 days now I believe. I've been having some cramps, nausea, and tiredness, which was how my first one started out. Should I wait a little longer, or should I take one now?