the way you have described things the only answer any doctor can give you is get a pregnancy blood test
You are most probably not pregnant -
Either your tubes are tied or if the doctor said one is growing back - then he should have put you on BC. He could only tell that with an X-Ray and die or an ultrasound
with contrast - if he didn`t do either he couldn`t tell. If he did and he made that statement he should have put you on other BC.
This is extremely rare - for tubes to grow back together - they don`t actually - you get small canules that develop next to the tube - but this is totally uncommon, very rare.
I would think it`s just the nerves, being frightened of being pregnant again, You`re an expeienced Mom-2-b - go get a scan that would even be better - because if your fluttering is originating from a baby`s movements you would def, be at leat 16 weeks - and any urine test would have to be positive!!
Ordo: blood test HCG
or scan -
Best of luck and talk to that doctor again about the tube that`s supposed to be growing back together again - that`s giving you sleepless night.