Please help!!! Pregnant ?

I had sex the 25 of Jan (cycle day 25) was fertile days 11-17 . my cycles are usually 35 days but because last month was short glow changed it to 29. so according to glow i was supposed to get my period the 30th . haven't gotten it yet , took a pregnancy test yesterday nd it came back negative . How long should i wait until I take another test ?