DP and I live in different parts of the country, so for day to day communication we what's app, call every other day etc.
Yesterday we chatted in the morning and he then messaged mid-morning to say he was heading out for the day cycling. I dropped him a couple of what's app messages during the day which I knew wouldn't go through until he got home and connected to wifi. By 10 last night they were still showing one tick (so not received at his end), so I texted instead. That went through but no reply. So at midnight I phoned and it rang out and went to voicemail.
I don't know what his evening plans were, but if he wasn't going to be around/uncontactable he'd normally message to let me know - he's very good for staying in touch - so the lack of contact is completely out of character for him/us.
The messages not being received at his end is what's worrying me as it suggests he hasn't made it home. I don't have any reason to think he's up to anything he shouldn't be, but obviously I'm now starting to worry that something's happened 
Less dramatic possibilities are that his phone died whilst he was out and he dozed off and didn't recharge it (happened before), but if he'd fallen asleep that early he'd normally be up and have messaged me back by now.
AIBU to be starting to freak out?