Hi. I Came Off The Combined Pill For A Month

Hi. I came off the combined pill for a month and didn't have a period. I am now back on the combined pill and having my first period since...however I am suffering from really bad cramps and a heavier flow (which is unusual for me). I just changed my tampon and noticed a clump of a flesh coloured tissue about the size of a penny. Is this normal or could I have had a miscarriage by any chance?