All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
It is better for anyone seeking to perform Hajj or ‘Umrah to assume Ihraam at the designated Meeqaat in compliance with the practice of the Prophet, sallallaahu ‘alayhi wa sallam, and his Companions . However, it is permissible to assume Ihraam before reaching the Meeqaat and it also does not affect the validity of the Hajj. Ibn Al-Munthir said, “Scholars unanimously agreed that anyone who assumes Ihraam before reaching the Meeqaat has actually entered into Ihraam.”
After assuming Ihraam, either at the Meeqaat or before reaching it, the pilgrim must avoid all the violations of Ihraam, like having sexual intercourse, applying perfume, wearing form-fitting clothes and the like.
Having sexual intercourse before the first (or minor) termination of Ihraam invalidates Hajj and the one must do the following:
The first termination of Ihraam is attained by doing two out of three of the following matter that a person in the state of Ihraam does on the Day of Nahr (10th of Tuhl-Hijjah):
Finally, having sexual intercourse after the first termination of Ihraam does not affect the validity of Hajj, but a sacrificial animal must be slaughtered and distributed among the poor residents of Makkah.
Allaah Knows best.