How true is this?

Li
So I'm on cerazette and have been for 8 months but I have been having a load of pregnancy symptoms including cramps, not much of an appetite, sore breasts, needing to wee loads (sorry tmi, but about 3 times every 1-2 hours) very tired.. Just not feeling me! And for the past 2 days I've been passing brown discharge which has now turned to spotting (blood now after sex) and I am experiencing pain on my right side near my hip, just below. I searched it and someone said the pill tricks your body to think your pregnant and then aborts the phantom pregnancy and that's what the spotting is? How likely/believable would you ladies say this is?