My boyfriend an i was having sex when we realize the condom break he took it off right away an put on a new one can i be expose to hiv or any std ?

Yes: Congratulations on finding a boyfriend. I hope you are happy together and perhaps your relationship will last a lifetime. But if he's worth keeping, you do need to know each others' health status. Time for a loving conversation -- hopefully it will bring the level of trust to a new level. In the usa, it's usually for folks beginning a relationship to get checked for HIV together.