What Are The Uses And Side Effects Of Sugar Placebo Pills?

Hi. So I missed a pill towards the end of the cycle last month then continued to take the 7 sugar/placebo pills without realizing I was supposed to skip these and start the next pack straight away! Have had extreme breast tenderness and fullness the past 2 weeks, fatigue, hunger, frequent urination, slight cramping today. Am due for period in 6 days. Could I be pregnant or paranoid?