Question of under review -situation
The time frame you mention is within what can be encountered. The time frames also differ wide between disciplines but also from journal to journal so one way to check how reasonable it is will be to check the journal for how long it has taken other papers to go through to acceptance. Many journals state this for each article and hopefully your journal does so as well. If no such information is stated you can try and ask a senior colleague who may have a perspective on the journals and their turn-over times.