Many birth control pills take about a month for them to be effective and you should use condoms up until that point. Since you are not getting your period, take a home pregnancy test to make sure you are not pregnant again. It is easier to get pregnant shortly after an abortion, so it's a good idea to take the test just to make sure that's not the reason.
If you are on a similar pill to what I took (a generic version of Orth Tri Cyclen) you period may not come for another day or so. I was a Sunday start, so stopped active pill on Saturday and first inactive (sugar) pill was Sunday. My period usually came on Wednesday, sometimes Thursday...so on the 4th or 5th day of inactive pills. I took them for 3 years and only 3 times did I get my period on Tuesday (day 3 of inactive pills). Every other time it was Wednesday or Thursday.