I've been searching my symptoms but nothing explains my problem. The closest thing is a uti. But I had just taken Plan B two days ago, and this morning ( 02/10/08 ) I held my urine in for a long period of time. Now, later on in the day I'm experiencing a very painful, achey, preassure-like feeling when I urinate. I am 14 years of age and am afraid to tell my mother or doctor.