When do I consider myself to be late?!

Ashley • Wanting so badly to have another baby! I`ve got baby fever!!
My last period was on April 22nd around 8 pm it started... By husband and I had sex again sometime towards the end of April and so forth... A few times, I've been somewhat nauseous at random times,  wondering when I'm considered to be late on this period, it's now the 22nd of May and no signs of my period coming ... Help lol