Question About Being Behind On Birth Control

[wildfire0414]

Hi, the past few periods I've had have not been normal. They have been 4 to 5 days late and I have been spotting inbetween periods. I haven't been taking my birth control like I should, I am 4 days behind on it right now but have been taking one every day, it's just not on the day I should be. How likely am I to get pregnant since I am 4 days behind on birth control? At times I feel like I could be pregnant but I took a pregnancy test about 2 months ago and it came out negative. Yesterday I had an egg white, milky discharge but it has went away, today I have been feeling bloated and have been having mild cramps. I would just like to know what are my chances of getting pregnant being 4 days behind on birth control and what I could do to get caught back up on my birth control? Thanks