Help trying to figure out ovulation

Sonia
So last month or had my period from the 14th to the 20th and I tested for ovulation on the 26 which was cycle day 13 and it was positive my period is irregular and has always been that way.. I'm supposed to ovulate today but my tests came out negative and I'm due to start my period on the 22nd. I'm so confused I've been testing since the 1st and all tests came back negative.. Help me should I test a couple days after i stop my period?