Should Levora Be Started As Scheduled Or Should The Periods Be Awaited?

I had sex on April 21 and the condom broke. I am on levora and I take it religiously and on time every day. When I found out that the condom broke, I immediately took 4 pills of levora and four more pills 12 hours later. I am supposed to get my period April 28, but I am late. I took a pregnancy test and it came out negative. Is it too early for the test to work? Should I start my new pack of birth control pills as scheduled or should I wait until I get my period to start a new pack again?