Is my husband having an affair?

Hi, My husband and i are together 5 years .We dont have kids yet because kids scare me right now and im afraid of doctors but i will have children but when i am ready which is bad cause my husband wants children now and i cant because i really am not ready he is 40 im 29.next to my problem my husband was divorced he was married to a thai woman he is not thai he is dutch,they got a divorce as things didnt work out between them and he had a child with her he dosent really see the kid but pays in the financial part his child is 10..since 5 months ago a thai family live near us infact right next door and theres a thai woman there she isnt married and i find my husband out a lot in the garden and in fact he seems to be coming home from work really late sometimes 3 in the morning he is an accountant i understand the job can be hard but i dnt know if accountants do overtime so late he should be finished at 9 ,im worried he could be having an affair as he is into thai women becuase he is too friendly with her and dosent spend much time at home or with me i feel i am losing him we dont have a love life of any sort.i asked him is anything going on and he says he is doing overtime am i blind? i dont know is he lying or not why is he having so many late nights what do i do am i just being silly but i really feel he is having an affair i asked him up straight and now he feels i am not trusting him ? HELP