OK, so I got a positive on my OPK test. I am on cycle day 13. According to the chart that came with the test, that would mean my cycle is 30 days. Now it also says that you can ovulate between 24-36 hours after getting a positive OPK result. So does that mean that my cycle is 30 days or is it 31 or even 32? I do not know how all this works as this is my first month off of the BC pill

TIA

Steph