As a personal opinion I think there are three factors affecting the choice.
First, Certifications are nice, often they can be achieved quite quickly and they may make your CV more attracting since you have proven specific knowledge on certain technology. The downside is that they typically aren't long lasting. What I mean is that the technology, focus areas etc. changes. So certificates are quite short term investments.
Second, continuing your educations. The lifetime of this investment is long(er). It takes time but also you get a wider perspective to your specific field and the surroundings. Upgrading for example B.Sc to M.Sc proves that you're able to do things but you can also percieve the bigger picture. Don't get me wrong, you may well percieve it already but it's not proven in a formal way
Third option, continue the studies but laterally. What I mean with this is that you study something that is related to the work you want to do but not the programming. As an example, if you're working with accounting systems, you already have the programming skills. What you could also do is to get a formal certificate on accounting related studies. This would give a new perspective to the solutions you perhaps already do and would prove to possible employees that you have wide expertise.
Which is the correct course depends largely on your personal motivations, social life, family situation etc. All of these will take time and effort, some more and some less. One question is, how much time you're able and willing to put on the studies.
Which ever direction you choose, one important thing is that you feel comfortable with it. So take your time to think about different options life has to offer
Best of luck!