Pregnancy Test Help!!!!

So I'm not really one to post on here but I need the help from other women. My husband and I have been trying since November with no luck thus far. As of right now I'm 7 days late. I have taken 3 tests (yes, overkill I know) and all have been negative. What would yall suggest? When should I take another test? When should I call my doctor if they continue to be negative combined with a no show from my little friend in red? Any comments would help!