Could I be pregnant?

Hey ladies just needing advice. I have a healthy 9 month old boy. Me and my husband have been together almost 7 years. :) Any way, I have regular periods every month. December 10/14 was my last one. I am five days late this month. I am never late! January 5th and 6th I had light brown discharge. Not much at all. Could that have been implantion bleeding? I took a test the day of missed period and yesterday, and they were negative. Could it be to early? My last pregnancy I didn't get a bfp tell I was six weeks! Did anyone get negatives? Then go to the clinic and get a positive? I was going to go to the clinic to get a blood test, but they said they will do pee option first and blood as last resort. Could I just have low hcg levels. Only symptoms I have is urinating more, tired, and Cramping bad around the time of my expected period. Are cramps normal early on?