Welcome to the forum.
As we have said in response to hundreds (thousands?) of questions, oral sex is safe sex -- not completely free of risk, but much lower risk for all STDs than unprotected vaginal or anal penetration. Oral is low risk for all STDs and zero for some.
Any "red spots" that appear immediately after exposure cannot be due to STD. No STD causes symptoms before 2-3 days. I believe you are correct about your spots being from friction during sex -- "wear and tear" is exactly right. Since they clear up within a few days, and never turn painful or develop into pimples and sores, that's additional evidence of minor trauma, such as broken blood vessels in the skin.
As for your groin discomfort, that also is not suspicious for STD. It is typical for genitally focused anxiety -- i.e. your concerns about STD risk probably are magnifying normal body sensations or minor aches and pains that you otherwise wouldn't even notice.
All things considered, I am confident you acquired no STD from this event. If I were in your circumstance, I would not get tested for anything and I would continue unprotected sex with my wife without worry of infecting her with anything. However, if you would like additional reasurance, you could see a doctor or clinic for examination and testing, such as a urine gonorrhea/chlamydia test and blood tests for syphilis and HIV. (This was a zero risk event for HIV, but HIV testing usually is automatic whenver any STD testing is done.)
In the meantime, don't worry about this. All is well.
HHH, MD
Yes, those things in theory increase the risk for some STDs, especially HIV. However, the risk from oral sex still remains very low, as described above. So this additional information doesn't change my opinions or the advice I gave you above.
Thanks for the assurance doctor. Though it was said that oral sex was a low risk activity, I have read some threads online (on some random website) saying that the risk of catching an STD increases when both the people have cuts which can exchange blood. As mentioned, I had tiny blood spots from friction and what if she had bleeding gums or sores in her mouth that I did not notice? I am not being paranoid, but this question is something that I never understood. I understand I am ok. Thank u once again...