*Sorry it's so long*

Hello, I'm 27 years old. 
Last January 2020 I found a small lump in my right breast so I booked a doctors appointment to get it checked. A few days later I attended my appointment, the doctor felt the lump and said it was very small and given my age very low chance of it being anything serious but still referred me to have a scan to rule anything out. I went for the scan, they said they found a small round shadow measuring 0.5cm x 0.5cm. They said they were certain it was a benign cyst but wanted me to go back in a couple of months to see if it had changed. Forward to a couple of months, I'd not long found out I was pregnant and covid had just started, obviously with no one knowing the effects of it at the time I was petrified to go to the hospital incase I caught it and would harm my unborn baby, so with this in my mind I stupidly kept putting off my appointment to rescan the lump in my breast.

Anyway.. fast forward to now, January 2021, whilst showering one morning I'd noticed that this lump in my breast had increased in size, so again I booked an appointment at the doctors. While the doctor was feeling it he said he's certain it's increased in size as it feels at least 1cm now and also feels like an oval shape rather than a circle. He again mentioned that given my age it's very unlikely to be anything serious but referred me back to the breast clinic again to have it checked.

I attended my appointment yesterday. As the man was scanning my breast looking at the lump on the screen he said "hmmm, how old are you again? 27?" Which I thought was a bit strange. He then told me he would need to take a biopsy or I would need a MRI scan but didn't explain why. As he left the room I asked the nurse if they thought it was a cyst and she told me that they don't usually take a biopsy if it's a cyst, but not to worry because it might not be anything sinister they just want to rule everything out.

After the scan I was called into a room with a consultant, who explained that they'd found a dumbbell shaped lump in my breast. One side of it consisted of fluid but the other side appeared hard on the scan so he gave me 3 options to either have a biopsy, have a MRI or go back in 6 months to see if anything's changed. I asked him what he would advise would be the best and he told me he's going to discuss their findings with some other consultants and then write to me in a letter what they have decided to do. He also told me he wants me to return in 3 weeks to see him again.

I'm not sure if I should be worried. Surely if it was anything sinister they wouldn't give me an option of returning in 6 months? Does anyone else have a similar experience they can share, and the outcome of their experience?

Thank you! X