Spotting at 15+5

Cr

So let me start by saying i have contacted my dr and they told me what to do, not to do and what to look out for.

2 days ago i had sex with my husband and today at work ( i work with special needs adults) i pushed 3 wheelchairs with people in them inside the building. The chairs are kind of a load but honestly i feel like picking up my 2 year old is more strenuous. My question is which do u think made me start spotting. It was only a tiny bit but still scared the shit out of me. So having sex 2 days ago made me start spotting or pushing the wheelchairs in the building?