What Causes Recurring Vaginal And Rectal Pain And Discomfort?

Hello, I am writing about a concern with my genital areas, I am 19 years old. I am week late on my period, and I am not sexually active so I know I cannot be pregnant. I have been feeling very sharp pains in my rectum and vagina. I was sitting on the couch and I felt the weird sensation coming on because this has happened once before, and when I stood up I could not even walk because there was so much pressure and I felt like my insides were about to fall out. Going to the bathroom is difficult but it is painful to push out and there is a lot of pressure. If I could imagine what a contraction felt like, this would be it. Is there a cause for this or any explanation/anything I can do? Please let me know any info on this, thank you so much!