Pregnancy i am pregnant

i posted this before but no one seem 2 reply to that topic anymore so that y i made this one
January me and my g/f where fooling around and i beleive i precum alot in her i did not ejaculate i made her take the morning after pill the next days. 3 days after she took th morning after pill she had a 3 day period ( she already had her normal january period ) the 3 days period ended on january 31
she is soposed to get her normal febuary period aorund 15-17 of febuary but that date passed and she still not have her periodi made her take the a home pregnacy test today and it came out negative ( she used two diffrent types of home pregnacy test with the saem unrine sample i believe)

Now wht i am wonder is that if she not pregnant that y hasn't she had her period yet for febuary some told me that when she took the morning after pill she had her period 2 weeks earier than expected could the 2nd period she had in january that lasted only 3 days be her febuary period

another think i wanted to know now accurate are home pregnancy test

i told her do another pregnancy test witha diffrent sample of urine to be on the save side

i am still a bit scared cause with missing her norma period and stuff kinda gettin me worried

and should i make her take a blood test to see if she pergnant
cause i readthat blood test are the most accurate ones