Can you have light spotting one day then a heavier flow the next?

I had some light spotting today it was a pinkish color. I thought i was getting my period at first but this has never happened to me. It's always heavier. And it was just a little spot then nothing else. I'm starting to worry because I think I might be pregnant. I've also been having a lot of cramping for the past 3 days. So is there a chance I'll wake up tomorrow and everything will be the same as usual?