6 days late!

I’m so nervous. We have been TTC for about 18 months and have failed over and over. I am now 6 days late on my period but I am just so scared to take a PT because I don’t want it to be negative. My cycle is usually around 31-34 days. I am now on day 39 of my cycle. I have yet to tell my SO because I don’t want to let him down again. I just know how torn we will both be if I am not pregnant and I don’t want to hurt both of us.