well in the league there is only chelsea getting more points ( one more) past sth like 10 games.. Saw the table elsewhere, Liverpool or Arsenal for instance got around 8 points less, don't the exact numbers... also we play great football creating loads of chances, only in some games we failed to score but that happens, certainly playing better than under Moyes and Vangle altogether and later years under Fergie when we were dire to watch, he himself said if we convert those unlucky draws in which often referee decisions didn't go our way into wins we would be sitting top or challenging with Chelsea...
I am sure you remember the start of the season, we lost so many points while trying to find our best side, nonsensical Fellaini and Rooney inclusions, unsettled Martial/Mhkitaryan, changing back four, Zlatan missing so many sitters etc... that's all IF IF IF but Mourinho has only came here, made some mistakes himself, but he seems to be learning from that and I'd be pretty surprised if we are far off from Chelsea in the second part of the season.
So no we don't look like we are challenging because we had a slow start into season and then some unlucky run of draws otherwise we look the best team in the league along with Chelsea now