Unprotected sex for few min. he didn't climax. put in spermicide half hour later. also 3 days after period. huge pregnancy risk?

Risk: There I'd definitely some risk but it is not huge. Just because you probably lucked out this time does not mean that that will continue to be the case. You need to see someone and begin a reliable method of contraception and use condoms to decrease the risk of STDs. If your period is late, it would also be a good idea to do a pregnancy test. The stress of worrying can make your period late.