I'm going to be honest. You sound like you have great anxiety or ocd. Is this the case? If so, it would be in your best interest to see a doctor to have that evaluated and treated. Fully. And if you are unsure, go talk to your doctor about it.
I don't mean to sound condescending - I honestly don't - but sexually transmitted diseases are called that because they are sexually transmitted. They aren't transmitted in other ways.
They also need human hosts, and gloves, speculums, etc., aren't human. The germs won't live on trash cans, transfer to the gloves, then to the instruments, then to you.
If you did get something (you didn't), you wouldn't show any signs of infection so soon that the spotting and cramping would be signs of it.
I agree with specialmom that this sounds like anxiety/OCD. If you aren't already in treatment for this, you should talk to your doctor about it. There is help out there.