I moved into a new place around 4.5 months ago. 

2 months ago I saw a roach nymph in a bathtub. Around the same time I saw there was a notice on the building that annual riach extermination will be done, sadly I wasnt home at t he time and only saw the notice when it was already done so they couldn't get into my appartment as well. 

I let my landlord know right away, and she called pest control and they came after a week, which was 2 weeks post seeing the first one and I saw 3-4 more within those 2 weeks, all nymphs, all in the bathtub. 

They also sprayed the common buildng areas and basement the 2nd time. 

Then I saw zero for around a week, and then suddenly one nymph every other day and one larger teen as well. They were all in the bathtub. 

So I called pest control and they told me that was normal, but it is common practice to do spraying in 2 rounds, just in case round 1 didn't kill those who were still unhatched. 

So 3 weeks after the 1st spraying of my appartment they came again and sprayed. 

Then a week later I had to leave for two weeks. 

When I got back, I found 3-4 dead nymphs on the bathroom floor, and one adult on the bedroom floor which was unpleasant surprise since I never saw them in the bedroom previously. 

They were luckily all dead. 

I ama wondering if this is normal? I know I was supposed to find them still after spraying because it takes time for them to die, but the one in the bedroom really shocked me.

Should I be worried extermination isn't working?