Hello I Took Plan B Around November 14th. I Got

Hello I took plan b around November 14th. I got my period November 21. My period lasted about 7 days. I had unprotected sex November 26, December 7, 18, 19. My period was suppose to come on December 19th, but I haven't gotten it yet. I went to the emergency room and I was treated for a yeast infection on December 21. I've taken 4 pregnancy test and they were all negative. I have lots of pregnancy symptoms (back pain, cramps, headaches, mood swings, cloudy urine, breast tenderness and I'm extremely moody). How long would it take for me to see a period, when should I test for pregnancy again, are these symptoms due to the plan b? Is there a chance I may be pregnant?