Welcome to the site.
Well, if you had your period after 19 days of sex then you are absolutely not pregnant because the periods had occurred after sex is not the case if one has become pregnant. So relax and just for reassurance you may get the pregnancy test done at home which will show you that you are not pregnant. You see slight delay or variation in the time of periods occur often, so do not worry, just wait and watch, i am sure the periods will start in the coming few days.
I hope this helps.
Wish you all the best.
Please kindly leave a POSITIVE RATING if you are satisfied with the answer.
I hope this answers your query as per your satisfaction, so kindly please leave a POSITIVE RATING if you are satisfied with the answer.