Yup it's fine. Recommend a steam before bed though, hot water in mixing bowl with a drop or two of olbas oil, a big towel over your head. A few minutes loosen the congestion and relieve your head aches.
I stupidly put some in my bath with me, smelled of olbas oil for days as it got on my skin. It also makes sensitive parts all tingly.
Also recommend saline spray if you get blocked nose or sinus discomfort. You can find it in toddler medication, squirt and sniff, it's uncomfortable but it makes things looser.
I would recommend putting a bowl of hot water with some olbas oil by the side of the bed so that the steam rises up as your trying to get to sleep. This really helped me
I researched whether olbas oil was safe or not as the bottle does say pregnant women should check. I found some people who said it was bad, but this was based on a starting point that ALL essential oils are harmful... Most people say its totally fine.