How long have you been doing the SIPs??
Are they in excess of four years and yet negative, then you should be worried.
If they have started in the last two years and still giving negative then you are on the right track as the markets have not been favorable and have gone down so it’s obvious the fund would have too. But that is a macro view.
Are the schemes you have doing enough to mitigate risk? Are they doing enough to stay close to their indices? are they very volatile funds?
these are the issues you will need to address to launch a proper evaluation.