missed period

Hello I'm not really good wording things I apologize in advance. So my fiancé and I have been trying to get pregnant for 4 months now and we tried every thing from eating healthy and being healthy he quit smoking and dipping and I quit drinking we taken vitamins and drink a lot of water we go to the gym three times a week and for this month my period was suspose to come on the third of this month but I'm 12 days late and the test shows negative he wants me to go to the obgyn and get a check up and talk about conceptions but I was wondering if anyone can give me tips and pointers so I don't have to go the the obgyn or should I go to the obgyn