Nauseous from Plan B over a week later??

Victoria

So I took plan B 10 days ago within an hour of our condom breaking. I was very nauseated for the first 24 hours which I knew to expect, but I didnt expect to be feeling it off and on still over a week later. Like its bad. I haven't puked from it but it just comes over me suddenly several times a day and I have to run to the bathroom or lay down. Should I be worried or is it common for this side effect to last? My period is 9 days away.