Are Hysterosalpingogram And Transvaginal Scans Painful?

I am 32 years and been married for 15 months now. Last year, I started having very irregular periods (could stay 3months without menstrating and I m not pregnant). On 17 of September this year, I started menstrating bt it stopped a few days and later continued. I visited a gynecologist and he prescribed premolut n tabs for me. I took it and after the 3rd day of taking it, the bleeding stopped. I had sex with my husband on Monday evening and at night same day, I started bleeding again till now. I m still taking the tabs bt I m so worried cause atimes the blood will just be spotting and atimes it flows like my menstal cycle. My breasts is also full, tender and atimes my nipples hurt. I was told to do a HSG and transviginal scan bt I m so scared as I learnt the scans are so painful. Pls help me as I m trying hard to conceive. Thank you.