Hi Nathalie, Welcome to HealthcareMagic Forum.
You have had sex on the 19th day of your cycle. You stand chances of getting Pregnant. This is the ideal time for getting it tested. Get a Urine Pregnancy
Test using a early morning urine sample. If it is Positive, consult a Gynecologist. If not, you may have missed your Periods due to Hormonal
Imbalance and stress
Avoid stress and maintain a healthy weight. Eat healthy nutritious balanced diet which should include fresh fruits and Green leafy veggies.
Wish you Good Health, Take Care.