Baby number 2?

So today is Tuesday march 9th, Sunday march 7 my then boyfriend now ex ejaculated inside my and got me a pill i drank it right away... I missed my period for almost a week and a half because on february 26 something stressful and scary happened so I'm guessing it delayed my period. I know the pill is 80% affective. i got my period today but do you guys think I'm safe after my period ends? When i started missing my period i felt strong butterflies and everything that i felt with my first pregnancy and i took a test and it showed a faint line and then i took twoore and they were both negative but the first test was equate and the other two were dollar general tests.. can you get a late period while pregnant??