Black-Headed Mointor(varanus tristis)

[agrrr1]

My pair of black-headed monitors have already laid 2 clutches of fertile eggs this season no problems.Now when she was due to lay her 3rd about 1 month ago(going on her size etc) nothing is happening while she does not seem sick she still eats although she can only fit in about 2 woodies.She has not eaten or moved from her log for 4 days now.She is by herself & gets heat 24/7.
If anyone has any sensible advice it would be appreciated.
Thanks