Depressed and sad after TTC for 3 whole years!?

So me and hub have been married for 3 yrs and we wanted to start a family and have the pitter patter feet running around in our home,but sadly after 3 whole yrs..still no little angel in our life.And i am to the brink of depression thinking abt this.Seen the Dr,checked and there is nothing wrong with me or hub..and yet...ughhh..i could cry if i continue this..