Irregular periods

So I had my last period on the 14/05/2019, and I am now 13 days late, I’ve set my Calendar to the right cycle but I’m confused at what is happening now. I had a negative pregnancy test in a&e at about 10pm at night & I’ve not been having an cramping just sore boobs and feeling nauseous all the time. Does anyone have any idea what could be going on? Should I wait to do another test?