My little sister took a hpt and it came up pos is there an infection that could make it come back pos when she wasn't

No it only tests for the pregnancy hormone...

It looks as though your sis is pregnant. Why would she be taking a HPT if she didn't think she were pregnant? Angel is correct in saying that it tests only for the pregnancy hormone (hCG) and that is produced only during pregnancy.

Your little sister needs to go to the Dr.

As everyone else said, it only tests for the pregnancy hormone. Its very rare for a person to get a false positive. Its time for little sis to go to the doc. She'll likely have to take a "proof of pregnancy" test at a clinic before the doctor will take her on as a patient. Then once they have the proof, she will start her prenatal care. Its important that she call the doctors, see where they want her to get this proof test done, and to start taking prenatal vitamins. (the sooner the better, esp if she is VERY young)

I agree with everyone else. Sounds like she is pregnant. Take her to get a blood test at your local teen clinic. Most are very cheap or even free.

Thanks for the input that I was rightbecause she lied to me then thanks

Take her to the emergency room and have them confirm it there. There probably isn't any infection...