AF symptoms or pregnant?!

Manda • I`m 30 and have 2 beautiful girls
AF was due on 30th Dec, still hasn't showed up which makes it the latest I have ever been. For the past week I have been feeling nauseaus daily, my breasts have doubled in size and are tender and yesterday I had to pee every 5mins!! I have also been getting cramping like AF is going to show, but then she doesn't! I took a test and a BFN so I'm just confused as to what's going on? We are really hoping for our BFP but it's when things like this happens it's really hard not to get my hopes up!