Feels like he's hitting a wall

So this one time I was having sex with my bf. He was hitting from the back aka (back shot or doggy style) and I had my face down in thw pillow and he's on the bed on his knees then he picked one of his legs up so now he has one knee on the bed and his other is in the air with his foot on the bed like the position a man is in when he's about to propose. But anyways when he did that idk what happened but his dick just felt like he was hitting a wall in my vagina like all the way in the back of my vagina, if felt like he was poking it with his dick and it hurt bag. A friend if mine told me he could be hitting my hitting my cervix but I need more opinions please help