Anxiety

My period was usually regular. My last menstruation was on January. But I wasn't able to have my period for February so I did a PT it was negative . Knowing it was negative I took contraceptive pills for the month of March. Again I did not have my period for the month March. So I stop taking pills. Then last April 1, I did again a PT and I was surprised that it was positive. Now I am worried that if I am pregnant is there a chance that the contraceptive pills that I took will have an effect to my baby? Please help me with my worries! Thank you in advance.