Clearblue OPK

Nicola • Married. 29 years old. Mmc at 11 weeks July 2015 and mc at 4+3 weeks Nov 2015. Pregnant with baby girl due 30.07.17 ♡♡
I've had 4 days of High Fertility but haven't reached my peak yet...is this normal? We have had sex on the high days but I presume I haven't ovulated yet? x