Mid-cycle spotting is sometimes associated with ovulation so you most likely were fertile at that time; not pregnant. If you had unprotected sex around that time it would be a high likelihood of pregnancy, however. The encounter of Oct. 30 would have been at a very unlikely time for fertility so, along with using condoms, you should be safe.
I would not be worried that something is wrong since spotting happens to almost all women at times.
The answers in online forums are for information only and are not intended to substitute for medical advice and care. Please see your personal health care provider for further evaluation of your individual case.
Debbie Miller, RN