hello doctor

I had unsafe physical relation with my partner on 11 april and last I got my periods on 25 th March but it was few drop and actual flow started on 4 april has I said I had physical on 11th April firstly I wanted know whether I should take the date on 25th March or 4th april to count my ovulation. After that I took ipill on same day on 25th April I got few drops after than no sign I did my beta hcg test on 3rd april is negative , just wanted to know what is correct week to do beta hcg test and whether I should go for test again