Root canal 2nd seating

[Ashu]

Hello, guys sorry for the thread lol, I wasn't able to come up with any since the situation I'm facing rn is kinda complex so have to go deep in order to explain what's happening, so the thing I am visiting a dentist for a root canal treatment and I was done with my 1st seating and 2nd seating and dr. finished my root canal treatment in not including filling and crowning in 2 seatings since my problem was not that serious but the thing is after my 2nd seating my dr. filled my teeth with calcium and asked me to visit in a week again for the 3rd seating but after my 2nd seating my dr. was on a vacation and after my 2nd seating I ended up having a hairline crack on my filling while I was eating something and there wasn't any choice since my dr. was in his vacation so the time passes by more than a week and before my assigned appointment i was tested covid positive and my appointment delayed the thin is that i don't know but for some reason i am having a sensitivity problem in my lower front teeth and i don even know in those hairline cracks food particles while i took shots if there are any there some yellow particles but it wasn't fully visible and which makes me think is that food particles are3 getting accumulated i don't even know if this sensitivity is coz of that the most i am afraid about is this coz of infection or something?