Hey i hav missed my period,and i want to knw wheathr am pregnant,plz help me?

am 24yrs old married since 8 months.my lmp was 25th march.On 29th march i underwent laprascopic surgery for bilateral ovarian cysts. on 17th april i had unprotected sex with my partner.its been 41 days nw i have not got my periods.i did urine test twice it showed negative.but i hav some symptoms of early pregnancy like tender breast and slight nausea.plz let me knw which is the best time to chk the pregnancy and how.