My 14 year old step daughter had sex 😕

EDIT; Praise God, she is not pregnant! They ran an std panel 5 days ago, so I'm guessing no news is good news. Thank you for your prayers and advice ❤ We are relatively close. My husband has full custody and she has lived with us for about 6 years. She was complaining "my vagina is itchy" so I assumed (with hope) that it is a yeast infection from wearing her wet bathing suit all day multiple times recently. Got her a 3 day yeast infection kit. She was acting WEIRD so I talked to her and she admitted to KIND OF of having sex...like he started to put it in and it hurt and she was scared and made him stop. I don't know how much I believe her that he stopped, but whatever, I got the jist. She has been a sobbing mess for days now. If her lady parts aren't feeling better this morning, her bio mother and myself are going to take her to the doctor together (her mother has no car and our daughter is on my insurance). I'm honestly nervous that she is pregnant and has an std (I've not said that to her outright, but if yeast infection medicine isn't helping and her symptoms don't match a uti then I don't know what else to think) She isn't in trouble, and I've not really even discussed my disappointment with her decision because I well remember being a hormonal teenager, and I don't want her to feel judged. For years we have openly discussed waiting until marriage, or at very least someone you love. The boy is not even her boyfriend. I know him and his mother and it's taking everything in me to not give him a piece of my mind (his mother would be LIVID). Any advice or words of encouragement would be greatly appreciated.