hi gagari, sorry about your situation. As your test results are negative or non-reactive relax a little and wait for 4 weeks and get retested or you can go for a more sensitive test like a Western-Blot technique or DNA-pcr
or confirmation. Getting yourself tested every alternate day is not going to help. It is ok to be worried but you should take hold of the situation and hope for the best. In future you should avoid unprotected sex with your wife and also your child will need attention and care. Take stock of the situation and follow action in a organised manner instead of getting nervous and making your life miserable. If after a month you test negative again or test negative by the before mentioned tests then you can still join the army. So don't worry about things you can't controll and take actions for those that you can.