I'm I Just Paronoid?

Can someone help? Is it possible to fell pregnant just two days after stopping the pill? I was on the pill for about ten years.The thing is I had a slight bleed after I stopped taken the pill,the following week I had severve stomach pains from then on a dull back ache,lots of burping,no discharge untill about a week later just a brown sort when I wiped myself and now again no discharge,i think the bumps around my nipples are more visible but not sure,a visible blue vein running to my nipple and mood swings.The thing is i've not been sick, not really that tired and my boobs don't hurt. Is this all in my head i've done two hpt's both negative but is this too early to detect my period isn't probably due for another two weeks! It's sending me round the bend someone please give me a bit of advise I haven't really got anyone else to talk to. Xx