Thanks for the query.
As there was no ejaculation and you took i pill
within 3 hours there is less possibility for pregnancy
Your symptoms could be side effects of pill.
You didn't mention any details regarding your menstruation
The pains could also be part of premenstrual syndrome
or due to ovulation.
So you better wait till your expected date of periods, if you miss the date you can go for test for pregnancy once, depending on the result you can go for further management.