What Causes Bloating,pressure In Stomach And LIghtheaded After Taking Plan B?

I took plan B about 2 weeks ago within a little over 120 hours. I know it is not suppose to be effective after 120 hours. In the past week I have been extremely bloated, with pressure in my stomach but can't pass gas as much as it feels like I need to, and feeling nauseated from time to time. I also get lightheaded sometimes. Can I have these symptoms from plan B?