Welcome to HCM.
You did almost safe sex, 5 days before period. However, pregnancy
should be ruled out through home pregnancy test or blood test
In this case, chance of implantation
bleeding is quite LOW as implantation occurs around D21 -D23. Late conception should be confirmed.
Hormonal imbalance, stress, PCOD, over weight, pelvic or vaginal infection
, change in eating habit etc may cause late period and above features.
Review with test results and consult with your gynecologist for next level management. Take healthy diet, proper sleep and avoid stress.
Be well and take care.