so when am i due

according to my lmp im due 21st april ... but i took an opk and it was positive on july 29 30 and 31... assume i ovulated 31st which makes sense as i didnt get my bfp until 14 days after this date .... am i due april 24th? periods were 31 days apart but sorta irregular sometimes 27 days sometimes 33 days but def got that pos opk