Hallow Dear,
At the outset let me explain you that in woman's private parts, there are two openings: one is for passing urine and the other is for reproductory function through which sexual intercourse is performed. This is called vaginal outlet. In a virgin girl, this vaginal outlet is covered by fibromuscular septum called as
hymen. During first (or first few) intercourse, the hymen gets ruptured and thus bleeds. This is normal and physiological.
If your boyfriend is not aware of these two openings and tried to insert his penis through the opening for the urination, it is going to cause you harm and burning micturition. You have to get confirmed that he tried through the vaginal opening only. In that case, the hymen has ruptured and hence you are bleeding. Nothing to worry about.
And baby, initial few intercourses are rather difficult for insertion due to the reflex contraction of vaginal muscles by a girl. If you keep them relaxed by keeping your mouth wide open, the discomfort will be much less. Moreover, use of lubricants will ease the penile entry. Oil based lubricants and soaps are harmful to girl's genital organs; hence use only water-based lubricants. Vaginal jelly available with the chemist is very good for this purpose.
I hope this helps you. For more detailed advice, you may ask me Direct question.
Dr. Nishikant Shrotri