I missed the last dark blue active pill on week 2 and the 1st light blue active pill on week 3. I took three pills the next day. I had unprotected sex the following day and my boyfriend came inside me. I didn't think about it until I started getting cramps the following day. Should I take plan b? This is the 3rd month on birth control pills, and so I'm not sure if I should worry that there's a chance of pregnancy. I talked to my boyfriend about it but we want to be really sure of a chance before we do take plan b. Please Advise.

If you missed 2 or more active (hormonal) pills
Or if you started a pack 2 or more days late
Take 2 active (hormonal) pills as soon as possible and then continue taking pills daily. You should take 2 pills on the same day. You may take one at the moment of remembering, and the other at the regular time or both at the same time.
Also, use condoms or abstain from sex until you have taken active (hormonal) pills for 7 days in a row.
If you missed the pills in the third week of the pack, you should continue taking the active (hormonal) pills in your current pack daily. When all active pills have been taken, discard the pack and begin a new pack the next day. You should not take the 7 inactive pills.
If you missed the pills during the first week and had unprotected sex you should use emergency contraception for maximum protection, in addition to taking today's active birth control pill.
Missed Birth Control Pill Guidelines

There's what you should have done. And I have yet to see a pack of because pills that doesn't have instructions for what to do if you miss pills. Any time you take any sort of drug, whether it be otc or prescription, you should read all of the info with it. You may very well have become pregnant. Even when taken correctly, no because is 100% effective. Taking it incorrectly only decreases its effectiveness. Now when did you have unprotected sex? Plan be is only to be taken within the first 72 hours after unprotected sex and even then the chances of effectiveness decrease the longer you wait. Also keep in mind that hormonal because does nothing to protect against stds.