Pregnacare causing spotting ??

So i had a chemical pregnancy and stopped bleeding on the 19th and i started to take Pregnacare on the 22nd. On the 23rd i had light spotting but only when i wiped and it only lasted a day and now on the 29th i am spotting again , a little heavier , im not due to ovulate intill 2nd November. I have never experienced spotting before . Could Pregnacare be causing this ? Has anyone else experienced this ?