It seems that no one ever really wants to answer the question of pregnancy likelihood throughout the menstrual cycle. It’s always THERE’S NEVER A GUARANTEE YOU CAN TOTALLY GET PREGNANT ANY TIME YOU BETTER USE A CONDOM AND YOU SHOULDN’T EVEN HAVE ASKED IN THE FIRST PLACE YOU PHILANDERING SCOUNDREL.
Surely somewhere there must be a graph of at least a rough estimate or mean average of the statistical likelihood of conception occurring from non-withdrawal vaginal intercourse for any Nth day of the cycle?
If you look into fertility awareness uses for people who want to get pregnant they have some of that info, but cycles are so variable from woman to woman and from month to month. In fertility awareness one tries to establish a basic understanding on their cycle including ovulation and something to do with vaginal fluid that is more conducive to allow sperm to reach and enter the uterus that is specific to them. It goes into the bast time to have sex to give one the greatest chance of conception. One may be able to reverse engineer this, but make a mistake this way and you will end up with a child, as opposed to just having to try again next month.
Because cycles are so variable between women and even from month to month in individuals - there really isn’t any way to average this information. A ‘textbook’ cycle is 28 days, 4-5 day period, with ovulation occurring on day 14, 15, or 16. This is what gyns base their treatment on, this is how they date all pregnancies (and will usually refuse to change your due date even if you are absolutely certain you ovulated very early or late). But the women who have a cycle timed this way are a minority (I have no idea if it’s 10% or 49%, just that no one I have ever heard discuss their cycle has a 28-day blah blah cycle).
The only real way to know when you’re ‘safe’ is to track your cycle and become familiar with signs of ovulation so you can reliably determine if you have or have’t yet. Really any time before you are sure you have ovulated could be a risk, although with religious morning temping you can usually tell a few days in advance when it will occur. A day after ovulation, until your next period, you are completely safe.