31w5d, baby is small and heartrate has dropped

I just had my 2 week check up and baby man is measuring a bit small for being almost 32 weeks. He’s measured on the smaller side for the majority of it, but I feel at this point he should be growing.

His heartbeat has also been 150’s through the entirety of the pregnancy and today it was 143. I know it’s not a huge change, but do I have cause for concerns given the information and is there anything I can do to ensure healthy weight and growth development?

Can’t help but worry. FTM and want to make sure I’m doing all I can for him. Thanks in advance for any thoughts/advice