Thanks everyone for your advice.
I will give a little update. DH came home on Friday night and she was heaps better, she did really miss him this time more so than other times he has been away.
A few weeks ago she kept complaining of being scared to close her eyes and having bad dreams so I did lay with her until she slept for a few nights until she told me that she can go to sleep by herself. I also bought her a pretty little dream catcher and hung it above her bed and explained that it will catch the bad dreams. She seemed to be better after that but maybe she is still scared.
The last 2 nights have been a bit of an improvement, she has tried to get out of going to bed still. Saying she isn't tired or she is bored. But I know she is tired as several minutes before she is yawning her head off. We did put her to bed slightly later last night and she didn't act up as much.
During the day we either go out, park/shops or visiting family. Then she has kindy 2 days a week but they are only 2hr sessions until she starts proper kindy next year. She also does swimming lessons. I try to keep her busy and active as much as possible during the day, but having said that for the first 15weeks of my pregnancy I felt terrible with morning sickness and exhaustion so we didn't do as much. I'm feeling heaps better now and the weather is much nicer so we will be spending a lot more time playing outside.
I'm 20 weeks now and getting a big baby belly so maybe that could be why DD is being more clingy and behaving this way because she knows that it will be a huge change when the baby comes?
Sorry for the long ramble, hopefully this week will be a better week for us.
DH is away again the week after that so that should be interesting