Period late 5 days

OK I'm TERRIFIED!! I have a 2 month old little boy. He is our world and we love him so incredibly much! Well, we fiance and I weren't as careful as we should have been, and I'm 5 days late. I KNOW I'm pregnant. I can just tell... I knew with our boy. So.. Can I take a test right now? What test would be best to take if I'm only 5 days late... I am NEVER late.. The last time I was late, my son was born. Sometimes it may be a day off... But never just miss it. Gah! Plz let me know what test would be sure to read accurately this early, please?!?