Yes you could be pregnant, if that's what you're wondering.
Steps you need to take:
1. Make that appointment! Stop waiting. Go in. Find out why you are not having a period if you're not pregnant.
2. While you're there, ask for a better form of birth control such as the patch or nuvaring. You clearly need something that is minimal-upkeep.
3. If you are on a new pack of pills, make absolutely sure you take one every single day. If it's a mini pill you have to be extra careful and take it at the exact same hour every day. You CANNOT mess up or you lose protection. If you're still on the old pack where you missed all of the pills, throw it away and start a new one.