Yes, often when focusing on body sensations, they can intensify. Your focus may be too hard. Instead, try to allow sensations to be there - like, notice sensations instead of focusing on them. I have a couple other suggestions re. meditation technique - If you want to continue practicing being mindful of body sensations, another technique (other than focusing where sensations are most obvious) is to scan the body. You will become aware of sensations elsewhere - even if you bring your attention to parts of the body where there at first appears to be no sensation. Another idea is to let your awareness rest below your navel, in the dan tien area (often described as four finger-widths below the navel). This is used a lot in Taoist and some Buddhist meditation. This is helpful, because by letting the attention rest there, the body's energy naturally becomes regulated and mind is calmed. Following the breath can have a similar effect, as you have noticed. It depends on what type of meditation you are practicing, and what tradition you are following. May I ask, where are you learning meditation?
Thanks, I will try those techniques. I could see it being perhaps too hard of a focus. The tense focus itself could be generating the feeling. During meditation (on the breath) itself I don't get this feeling and it is generally blissful.
I am currently following instructions Mindfulness in Plain English. The specific technique of following the physical sensations of emotions I read in a book by Jon Kabat-Zinn.