I had my mensus date on every month 22nd and the ovulation had come on 5th of next month I had a sex with my boyfriend yesterday i.e (on before one day of my ovulation).. and we had done unprotected but before ejaculation he stopped it but anyhow I have a doubt that he might be ejaculated in... but there is no vision of siemen on my vagina even how I have a doubt and lot of fear... please help me whether I get a pregnancy or not..?

And what should I do in order to stop getting pregnancy if in case..?