I took plan B about a month ago and took 3 prego tests that came up neg so i know im not prego but I am now experiencing constipation issues and some abdominal pain not incredibly painful but its there. Sometimes i will not "go" for 3 days and when i finally do it is bloody and i have to force it out (gross i know). Is this just a side effect? I did not read "constipation" as a side effect on the box. Please help. Thanks