My hubby says he wouldn't worry if he was you :)
Hi!
Usually there is no cause to worry. It all depends on when this happened. If it happened a week after the end of periods, then your partner was in her fertile days (if she has a 28 day cycle). At this stage if your pre-ejaculate contained sperms (less likely) then this can make her pregnant.
Pecum is a clear fluid secreted when a male is aroused. In chemical composition it is close to semen but has no sperms in it. If a person has ejaculated in the last 24 hours, then some sperms remain viable in his urethra. These sperms may mix with the precum or preejaculate fluid secreted subsequently while this fluid passes through the urethra. So if a person has passed urine several times or if more than 24 hours have passed since the last ejaculation, there will be no alive or viable sperms in the urethra. However women are known to get pregnant if the precum entered their vagina and the man had masturbated in the last 24 hours or had normal sex and had not passed urine since then. Hence though the quantity and quality of sperms is not good enough sometimes, it may be good enough to cause pregnancy especially if the man had ejaculated in the previous few hours and the woman was close to her ovulation. So, if your periods delay beyond 4-5 days (some delay is expected as you are stressed out) then take a pregnancy test and see. Hope this helps. Take care!