Thanks for writing to us,
It is normal to have bleeding on intercourse during menstruation
The menstrual cycle fluctuates between a period of 20 to 28 days.(in your case 19 days)
The fluctuation is due to hormonal
imbalance, have an healthy iron rich diet like dates, milk, jiggery , etc,.
If your spotting wont seem to resolve, increasing in next cycle, get an gynecologist opinion.