I took postpill 3 times in 2 weeks before my period which i was 3days late and hard a very light period for three days could i be pregnant or am reacting to the pills?

Yes to both Time will tell..

"Postpill" has high levels of hormones which, taken after unprotected sex, prevents your ovaries from releasing an egg or prevents fertilized embryo's from implanting in your uterus. The high hormone levels commonly disrupt the menstrual cycle. This can result in irregular bleeding, breast pain, nausea and other symptoms. They should not be used frequently.