Could I finally be pregnant?

Hi there. Me and my fiance have been ttc for 3 years. I have endometriosis but had a laprascopy and removal done in december last year to help us conceive. I'm very regular with my periods and they're always so heavy.

This time I took a small dark bleed for 4 days in the middle of my cycle but it was enough for me to need a pad on.

I am now 4 days late for my expected period and I've really funny wee flutters and a dull pain on my lower left side and my lower back is aching 24/7.

Im not going to test until Friday as that's when I'm paid from work again and I'm scared of another negative to be totally honest.

But for someone so regular and who has literally just stopped actively trying last month as it's my wedding in 9 months I'm wondering if it's actually happened and have we actually conceived our wee bean?

Can I have info on anyone else who had similar symptoms? Thanks. X