18 could I b pregnant ?? help need lot of answers?

my last period was on the 26th of last month I'm due on the 23rd of this month . I had unprotected sex June 4th 5th 6th 13th 15th & 16th . every ovulation calendar said I was fertile all those times . I was ovulating on the 10th but idk how true the period tracker app is. what's the chances of being pregnant ? when should I test ?? what do u think ? what's the best test to get ??