I'm not sure if I've been sexually abused? How do I know for sure this happened to me?

If you have a trusted adult you can go to talk to them about what has happened. You could also talk to a doctor, therapist, or other professionals who can help you to determine what has happened. But if something has happened that has made you feel violated and uncomfortable then regardless it is not right for anyone to make you feel that way. Make sure you create boundaries and tell whomever that you are not comfortable when they act or do certain things. I hope everything works out and you get the answers that you need to help you through your life.

Your feelings associate with the event are valid. It can be really difficult to label the event as sexual assault, and in fact, you don't have to label it like that in order for it ad your feelings to be valid. You define your own boundaries and your mind and body will sense when those boundaries are crossed. Additionally, connecting with others who have gone through similar situations can also help with identifying how your boundaries were crossed. Sometimes hearing other people who went through there same thing call their experience sexual abuse can validate your own experience and emotion.