I need advice !!

I'm 24 currently have a 5yr old and a 3 year old , my fiance has a 3yr old and a 6 month old baby from a previous relationship. Is a little complicated because we are trying to get an apt and we stumbled across a house that will soon be our to rent god willing. I am now trying to concieve because we want one more I just been a little worried because it may not be the perfect moment to have a baby even wanting it so bad. The thing is to my belief I was supposed to fall on my period already about 2 days ago but then again I'm irregular. Idk what to think . advice's please on the whole scenario. Thank u.