Anna,
It is very common to regress a little bit after introducing solids. This will probably happen on several occasions, and is not really something to worry about. I think you can minimize it by trying to realx about it, just offering the food, and if your lo doesn't want it then no problem.
At this point your lo is just getting the feel for foods, not really getting any nutrition from solids. So it is 100% safe to take his cues on what he is ready for.
One more thing, do you eat with him? If you can, you may want to time your own lunch or dinner when he would have his. Then offer him little tastes of what you have, or let him hold on to something that he can put in his mouth such as a cucumber stick, a rice cake, etc.