Hey Martin!
Mine took a little longer as they requested more passport photographs off me. Have the requested anything more off you? If so once they receive the requested photographs/documents the 3-6 week restarts. That is what they told me when i called to find out.
If nothing has been requested, a friend of mine had her FI a day after mine and she still up until this day hasn't heard back but it still says approval in progress & no news is genuiley good news. Just keep waiting but if it really stresses you our call your HR & try and find out
xx