As you mentioned you are overdue by 8days and had an unprotected intercourse
, there are chances that you can be pregnant. You took a pregnancy
test couple of days back which might have been too early to be positive. I suggest you take a repeat urine test for pregnancy with early morning sample or get a blood test
for beta hcG
to be absolutely sure. Though a urine test is almost always positive when you are 8days overdue. Moreover you had unprotected sex during your fertile period which further increases the chances of pregnancy.
The idea is to rule out your pregnancy as soon as possible so that you can take appropriate measures as medicines used to abort unwanted pregnancies are more safe when taken early and under supervision of a doctor.