Yes it will definatley be panic, I get exactly the same and you would think after all this time you would know the difference between those pains but you really don't! You said yourself you were petrified, and I cannot remember the last time I felt petrified and that didn't go along with feeling S* and having pains.
Please don't feel like a bad mum, you really are not, and there are so sooo many other mums who are exactly the same in your situation, I know myself as soon as my fiance says he feels nauseous I literally apologise to him and pack a bag, its so horrendous and I feel so terrible but it's just one of the bad things that goes along with this phobia, its fight or flight and we are all trying to conquer it to the point where we can stay and fight, until then though at least we have each other to vent about it all and totally understand