Af showed up...plus Dr appt stuff....

So I'm out. Af showed up today. 5 days early. Which then led to me scrambling to get on the phone with the Dr to schedule my hsg and all my blood work. Thankfully our hospital has a lab open on Sundays so my cycle day 3 tests can be run when their supposed to be. Waiting for the Dr to call me Monday with the appt time for the hsg. To any ladies that have had the testing done is there anything I need to know about before hand? More specifically regarding the hsg testing? I was told if my tubes are blocked it's going to hurt a lot. True not true? Any advice? Thanks.