Accepted an offer and now a new opportunity - help!

[QwertyQueen]

I have been self employed for about 12 years.
I have recently decided to go full time as I am now a single mom and I need a consistent income so I can budget and plan.
So I have been interviewing on and off for months… in a good position in that I have a lot of free lance work so am not desperate.
I interviewed with company A a while back - it has been a very intensive process with psychometric testing, technical testing and so on.
They finally made me an offer on Friday and I said I would give them an answer today. They pushed me a bit saying they rally wanted me to join the team and were hoping to get a response (as I they had upped the offer after my initial hesitation).
They are a great company to work for: flexible hours, good reputation etc. There are a few down sides of course and it is not a very senior role, but I think there is room for growth in the company.
So I, on the phone, said yes I will accept.
Literally an hour later my phone rang and it was the husband of a friend of mine saying he heard I was looking for work and his company (Company B) will be looking for someone that does what I do imminently and can he set up a meeting.
Now Company B is an international company, also with a great reputation.
Probably a smaller, more dynamic office than Company A.
I have told company A I need until Wednesday as I need to consult with a financial advisor, and now company B have said the soonest they can see me in Thursday. Arrrgh.
Company A are getting anxious, they keep telling me how much they want me to join, and I am feeling so stressed and guilty about the situation.
The last thing I want to do is mess anyone around, but if I had a choice I would choose Company B.
But it is just a meeting. We might not fit, the money could be less (although I suspect it would be more), they are not in a rush to find anyone.
My friend's husband has suggested I accept Company A's offer, and then if Company B does offer me something I can move.
But that feels wrong to me, I don't want them to invest in me and then I leave.
I guess I have to wait until Thursday and see how the meeting goes.
I can't be honest with Company A and tell them what is happening can I? They will think they are my 2nd choice.
Sorry this is so long, but if anyone has advice it would be greatly appreciated!

[BlueBlueSea]

If you keep company A waiting and tell them they are second choice to another job interview, you risk loosing that offer.

I would suggest accepting offer A, don't sign the contract yet. Go to the interview with company B, if you still want company B at the interview, tell them that you have another offer and see when they can give you an answer.

Then if Company B offer and you want it, just tell company A that you have had an offer you can not refuse. It does happen, they will be pissed off but can not stop you.

[MindfulBear]

Accept Co A, agree a start date 4-6 weeks a away and then pull out if B offers. Also impress on B that you have done this so they must not mess you about and speed is of the essence.
I have done this and kept it really amicable telling A what a great opp B was offering and I had always wanted to give it a try. 2 years later I am about to join Co A!!!!