- "she was pretty wet down there ... this probably raises the risk of her getting pregnant" That would be true if it were at a fertile time.
- "is the risk still 'likely' or 'highly unlikely'?" Highly unlikely
- "she's FAIRLY regular ... usually ... around the same time each month so I'm guessing it's around 30 day cycle" Probably. There or thereabouts. That would indicate that 27th was almost certainly not a fertile day.
- "once in a while it shifts and she gets it later or earlier" Months vary. 7 month have 31 days, 4 months have only 30 days, and 1 month has 28/29 days, So even with a regular cycle periods would start on the same day every month,
It is extremely unlikely she would be pregnant. I would expect her period to start in the next day or two.
- The fact she had her period would indicate she is probably not pregnant.
- "wondering if skin to skin grinding (by this I mean penis to vagina)" Do you mean 'vagina' or 'vulva' (or what)? Her vagina is the birth canal, and if your penis tip made contact with her vaginal opening, then pre-cum could have entereed her vagina (which would presumably be wet).
- "we did it on Dec.18th & on Dec. 27th" If her period "started ... on the 31st" then 18th probably wasn't (& 27th most certainly wasn't) a fertile day.
- What do you mean by "her period was going to start on the 27th"? How do you know (or reckon) it was going to start on 27th?
- "I know I urinated both days" Before or after your sexual encounter? Urination would clean the urethra of any residual semen that might otherwise mix with pre-cum.
- "didn’t ejaculate that day or near her vagina" I am not sure what you mean exactly. If you didn't ejaculate that day (which day?) you couldn't ejaculate near her vagina (or near anything!)
- "there was no penetration involved" Penetration by penis or fingers? Penetration isn't necessary as sperm near the vaginal opening can swim in.
- "precum can contain small amounts of sperm" It certainly can. Some research has indicated that some men always have sperm in their pre-cum.
I hope this helps a bit. I think she is not pregnant, but you do have to be careful
5) Before the encounter
6) Sorry, I meant to say that I didn’t ejaculate before the sexual actions on both days, but did urinate before the sexual actions both days. All semen ended up on me the 18th and on the 27th a lot ended up on me and some on her hand, but after that she washed with soap for a good two minutes and that’s when all stopped.
7) Penetration by fingers which had dried precum and I wiped them off on the floor and blanket near us.
Pleased to help
Take care
I am not sure what you mean by "enough time to prevent the period if she had been pregnant". You state she had her period on 4th, so nothing "prevented" it.
In the normal course of events, a period comes about 14 days after ovulation when the woman has not become pregnant. Her period is the discharge of her womb's preparation for pregnancy.
If her period naturally started on 4th Jan, it would suggest that ovulation occurred on 21st Dec, and so sperm entering her vagina on 28th would not encounter an egg to fertilise.
If EC were involved, then that pill might prevent ovulation and induce a "hormonal period" at an unforeseeable time. If sperm entered her vagina several days before a period starts, and there had been another ovulation in that month, then it is just possible that an egg could be fertilised, but would probably find it difficult to implant in an ill-prepared womb. If it entered very close to the period-start, and the cycle were very short, it could just be possible that an egg released during the period could get fertilised.
However, you'll need to recap the "event", the actual dates involved, and her period history & forecast due date. Anonymous posts are hard to keep track of, and I respond to a number of similar cases. So far as I can recall & review, "events" have happened on the 27th, and you refer to 28th.