If you have been consistently measuring behind, then measuring behind is not a big deal. What we don't want to see happen is a baby that was developing at a certain pace that suddenly seems to be dropping behind. That's not what is happening here, your baby is developing on a set pace and that is all good.
Think of this like riding on an airplane...if you're taxi-ing on the runway that is fine. If you're soaring along at 10,000 feet that is fine. What you DON'T want is to be at 10,000 feet and then suddenly look out the window and see the runway coming at ya! THAT is a bad sign LOL. But driving along the runway when you've been on the runway all along is just fine.
It's most likely you Oed 2-3 days after your attempt and then the rest is just individual variation.
Baby's heartrate is absolutely fine and normal (if anything above average, which does NOT mean anything bad!) Baby's heart naturally increases from 90-110 in the 6th week up to 140-170 by the 9th week.
