Need some advice. Kinda freaking out here!

(Me and my fiance have one son who is seven and also have had two miscarriages within the past year. We are not technically trying but at the same time not avoiding it. We together felt the stress of trying was too much and felt it would be better to see if it just happens.)

So last month I had my period one day early than usual and it only lasted 1 day when it usually last 3-4 days. I took a test a day after and it was negative.

Now I have had sore breast for over a week and have had diarrhea for a couple of days now and my period is due in 3 days if it's going to be my normal 28 day cycle I've always had except last month.

Now I'm freaking out because I'm worried if I am pregnant that I have been drinking on the weekends and recently had a cold so took medication because of the negative test I got last month didn't see a worry until I started feeling these symptoms.

Any advice or comfort would be nice. Thankyou