On my mytodex eye treatment in the label indicates that discard four weeks after opening, can I use it again now? Its not expired but can i, is it safe

Med use. The medication is likely still fine as long as it was not contaminated by touching it on your lashes during it's previous use. If you are not sure, get a new one for use.
No. I never have patients use eye drops for very long. Once opened, they can all grow fungi or bacteria, despite the preservatives in them. Get a new bottle.