still no period....

MELINDA

so I'm over a week late. taken 4 tests. all negative. I'm tired, mild cramping like I'm going to start my period, slight nausea. but no positive tests. I'm confused. also tired of getting my hopes up. we have been trying for year. also we only had sex once last month. but it was during ovulation time according to my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period app</a>