10 days after ovulation (or 4 days before your period is due) is the earliest to test and you'll need someting that is sensitive enough for that such as first response.
Implantation occurs approx 10 days post ovulation.
You say you had your last period around he 10th may and the condom split on the 24th - that is exactly when you would be expected to ovulate in a normal cycle - right in the middle of your fertile window.
So yes, you are high risk of pregnancy. However, you still have time to get a coil fitted if you wish to prevent the pregnancy from implanting (it needs to be done within 10 days of unprotected sex).
Or if you want to keep any possibly pregnancy then sunday would be the earliest day to test - make sure you use the first urine of the morning so it is concentrated and the test has a greater chance of picking up on those hormones.
Otherwise, if you don't have such a sensitive test, then you need to wait until thursday really.