Looking on the internet deeply has found these results:

in the past few months is the most popular phrase on the web.

in past a few month 11,440 results on the web	in the past few months 16,950,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
These past few months are obviously some of the worst ever. These past few months have been amazing. Had been running almost every night for the past few months. We've been trying to track him for the past few months. It's where I've been for the past few months. We know it's been tough these past few months. The past few months, Bobby has been different. My travels and travails over the past few months have proved more than a test of faith.	About 30,000 German rifles have been landed at Larne, County Antrim, in the past few months. I've imagined saying that a hundred times in the past few months. I sincerely thank you for all that you have done for me in the past few months. We've slept together a thousand times, and you've thrown Andrew a bone, what, once, twice in the past few months? I've been praying a lot to help me in the past few months. To celebrate all the progress you've made in the past few months. Mr President, in the past few months my fellow Members and I have met a great many representatives of the motor industry. Sensei, in the past few months, we've taken down giant spiders, plant creatures, alien robots, and an army of ninjas.

in past a few month

11,440 results on the web

in the past few months

16,950,000 results on the web

More popular!

These past few months are obviously some of the worst ever.
These past few months have been amazing.
Had been running almost every night for the past few months.
We've been trying to track him for the past few months.
It's where I've been for the past few months.
We know it's been tough these past few months.
The past few months, Bobby has been different.
My travels and travails over the past few months have proved more than a test of faith.

About 30,000 German rifles have been landed at Larne, County Antrim, in the past few months.
I've imagined saying that a hundred times in the past few months.
I sincerely thank you for all that you have done for me in the past few months.
We've slept together a thousand times, and you've thrown Andrew a bone, what, once, twice in the past few months?
I've been praying a lot to help me in the past few months.
To celebrate all the progress you've made in the past few months.
Mr President, in the past few months my fellow Members and I have met a great many representatives of the motor industry.
Sensei, in the past few months, we've taken down giant spiders, plant creatures, alien robots, and an army of ninjas.