Mast cells. Mast cells and basophils are generally thought to be the major sources of histamine and can themselves be modulated by histamine as they express H 1, H 2 and H 4 receptors, although how this varies between different mast-cell types is not yet clear.
3. The pill is to be taken soon after unprotected sex. It should be taken preferably within 24 hours and before 72 hours or else the pill may turn useless. 4. I-pill checks pregnancy by preventing ovulation or fertilisation or implantation of the fertilised egg. 5. I-pill is 95 per cent effective if taken in time.
226 thoughts on âHow soon are you safe after starting birth control pillsâ. I started the pill on the 23rd of august and got caught in the moment of sex and my boyfriend came in me. (This was one the 28th of august) i had sex 6 days into using the pill.