Help me someone plz

This app saids I'm three weeks pregnant and some days and yesterday I got a neg test??? Is this app true about what it saids or is it fake??? HELP I SONT KNOW WHAT TO BELIEVE I WA ON BIRTHCONTROL DOR A MONTH IN A HALF AND I STOPPE TAKING IT JAN THE 19 I had my period Jan 15-18 and I ovulated the 29th of Jan and five days after I ovulated I had little sports of blood on tissue and the sixth day I woke up with sore boobs hello can someone help me