ttc almost 40

Hello I'm 39 trying for or fourth baby my husband is 44 we have a 11 year old a 8 year old and a 4 year old I'm a stay at home mom I homeschool all three kids husband works it's been a year since we have ttc right now I am 9 weeks late doc did a pee test last Friday and was negative still no af no pregnancy signs but I have been there with all three kids home test were negative till about 12 weeks so I'm keeping my fingers crossed