I had intercourse 4 days before my period started, I had a regular cycle. I then started my period the next month and had a regular cycle. This month I am 3 days late. Is there a chance of me being pregnant ?

3 days isn't late. I highly doubt that you are pregnant. It would be extremely rare, although a few women do experience what seem like periods the first month, and sometimes more. You might even skip a period this month. Being regular rarely lasts forever.