This is very similar to me. Near the end, I'll tend to say things like "I know we only have a few minutes, but..." or "I know we have to stop, but..." to show I'm aware of the time. The few times that T's (current or ex) have said we had to stop without my saying anything made me feel really bad. Occasionally, my current T will say something like, "Is this an OK place to stop?" or "OK if we schedule now?" when I've reached a seeming stopping point.

My former marriage counselor would often go over time considerably, like 10-20 minutes, even longer at times (but not always). So with him, I'd use the "I know we have to stop soon" to sort of test whether he was allowing us more time that session. To see if he'd then say "we still have time." He also often started sessions late (due to giving other clients more time!), so if I didn't pay close attention to what time he actually took us back, I sometimes wouldn't be sure when the 45-50 minutes would be up.