Spotting on 5th day after eating ECP

Hello,

I need urgent help. Please tell me what my body is going through according to the description below. 

I took the ECP on the 26th and today is the 1st and its been 5 days. My monthly period is due on the 7th. I have been having severe cramps since morning, but no bleeding in flow.. just some spotting like my period takes a start. It is not heavy or anything and at first it was brownish now it is light reddish. 

I had taken the ECP as a safe measure and I didnot have intercourse with my husband. He was wearing a condom and he just ejaculated outside my vagina, but we thought there was leakage so I took the pill. Overall, just a safe measure.

Now, im worried that spotting and cramps have continued throughout this day and I want to know whether this is actually implantation bleeding or just a side effect of the ECP pills I have taken. Also, will my periods gets normal and what about for this month on the 7th?? If they arenot normal in quantity or timing then what measures should i be taking.

I had taken the pill about 2 months before too and at the time I had gotten my normal period without any side effects except minor abdominal pain and nausea. 

PLEASE HELP ME UNDERSTAND WHAT THESE SIGNS INDICATE.

I'D BE VERY GRATEFUL.