Periods after 12 days of having periods.

Hi, I am getting periods like bleeding since yesterday while my periods finished on 30th June only. I don't have any pain except normal fatigue and sleepiness. During the early years of my cycle, they used to shift 4 days every month. Once about 10 years back I missed them once. Since then until now, every cycle has been normal. I am sexually active and had last sex on 3rd July. It was with protection and there was no mishap there. The bleeding is fresh red blood and heaviness matches my day 1 period. I wonder if I should get a pregnancy test done,if yes, when would be the right time to do it. When will be too late for abortion if pregnant. Can I have some other infection etc? I never had any hormonal imbalance condition. No other condition as well. I got vaccinated with Covishield on 21st June.