If the ring was still in place when you had the intercourse and for a day or two afterward, you are protected. You can expect your withdrawal bleeding to happen since you have lost the ring. Soreness of the breasts can be a symptom of an impending period. Please see a specialist for further support. You will need a pregnancy
test if you do not see your period and you can also get it done three weeks after the intercourse. Hope you find this information helpful. Take care.