Hello,
This spotting can be due to implantation bleeding. You can test for pregnancy by a highly sensitive pregnancy test 10 days post ovulation with a sensitive ( 20 - 25 mIU ) pregnancy test. Also I would suggest you to get your serum HCG levels estimated since this is more specific than urine for pregnancy tests. The HCG (it is a hormone) levels rise only in pregnancy and its presence will confirm the status of your pregnancy.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing
If you did have implantation bleeding (it's not that common) a week before your period is due is a little early to have it - then again, you could have just ovulated earlier therefore implanted earlier than you though.
Just because you have symptoms of pregnancy doesn't mean that you're pregnant. Many things can also mimic the symptoms of pregnancy. All you can do is wait till next week and if your period doesn't show then take a pregnancy test with first morning urine. You're right about a blood test being too soon - you can't test till at least 2 weeks after intercourse to get an accurate answer.