Early period

I thought I was experiencing early pregnancy symptoms, cramps, Acne, some nausea, exhausted. On Fri at 11-12 dpo I had a some spotting when I wiped, nothing much. I thought maybe implantation. Then early Sunday morning I had sex, some spotting after, during the day I spotteda little off and on, Sunday night it was more red blood, like my period, but not heavy or clots like normal, I had a light flow(maybe filled a whole pad threw the day if I hadn't changed them more often) today's the same, its getting lighter. So it started 3 days early for my period and its much lighter than normal. I'm usually 28 days on the dot, the 1st and 2nd day is usually very heavy, I have to wear a tampon and pad to not leak at work and it Normally lasts 5 days. Any idea whats going on? I didn't test, after I saw red blood i figured I was out, but with it being so abnormal, for me I'm confused.