Hallow Dear,
The
hymen is situated just inside the vaginal opening. In most of the cases, the hymen is a very delicate fibro-muscular membrane having a small opening in it for the passage of menstrual blood.
Hymen is so delicate that it gets ruptured by the entry of the penis during first intercourse. However, sitting astride like bicycling, two wheelers riding, horse riding, exercises like tree climbing, athletics etc. also may rupture the hymen. So in this era, most of the girls have their hymen ruptured before the first intercourse.
If the hymen is not ruptured even after the insertional intercourse, there possibilities are:
1. The penis might have just touched the hymen and not entered inside the vagina. This can happen if the hymen is too tough also. Even after such intercourses also,
pregnancy is known. Most of the cases, the full penile entry is not achieved for many months.
2. The hymen may be imperforate hymen. However, in such situation, the girl will not get menses.
3. Most likely possibility is that you could not inspect your hymen properly. Hymen does not look like a skin, it looks pinkish, like a muscular membrane with an opening in it. After rupture, the edges of hymen are withdrawn to the vaginal outlet walls.
I hope you have got a detailed information.