Pregnant or no?

So I haven't been on my period since the 23rd of December. I am extremely late and still haven't had any signs of starting any time soon. I have taken multiple home pregnancy test and they all show negative. I have no clue what I need to do, because I feel I am pregnant. Help please? I have been sick, nauseous, vomiting. Extensive bathroom visits. Occasional mood swings (only when I don't feel good) any advice on what to do, or causes of something else?